diff --git a/accessible/base/NotificationController.h b/accessible/base/NotificationController.h
index 60684fba78ed..a83490fdd317 100644
--- a/accessible/base/NotificationController.h
+++ b/accessible/base/NotificationController.h
@@ -367,10 +367,7 @@ private:
     typedef const T* KeyTypePointer;
 
     explicit nsCOMPtrHashKey(const T* aKey) : mKey(const_cast<T*>(aKey)) {}
-    nsCOMPtrHashKey(nsCOMPtrHashKey<T>&& aOther)
-      : PLDHashEntryHdr(std::move(aOther))
-      , mKey(std::move(aOther.mKey))
-    {}
+    explicit nsCOMPtrHashKey(const nsPtrHashKey<T> &aToCopy) : mKey(aToCopy.mKey) {}
     ~nsCOMPtrHashKey() { }
 
     KeyType GetKey() const { return mKey; }
diff --git a/dom/animation/PseudoElementHashEntry.h b/dom/animation/PseudoElementHashEntry.h
index a576e9c572cd..63f9c60c80e0 100644
--- a/dom/animation/PseudoElementHashEntry.h
+++ b/dom/animation/PseudoElementHashEntry.h
@@ -24,7 +24,7 @@ public:
   explicit PseudoElementHashEntry(KeyTypePointer aKey)
     : mElement(aKey->mElement)
     , mPseudoType(aKey->mPseudoType) { }
-  PseudoElementHashEntry(PseudoElementHashEntry&& aOther) = default;
+  explicit PseudoElementHashEntry(const PseudoElementHashEntry& aCopy)=default;
 
   ~PseudoElementHashEntry() = default;
 
diff --git a/dom/base/nsDocument.cpp b/dom/base/nsDocument.cpp
index e2df0ed9e922..5676421a8940 100644
--- a/dom/base/nsDocument.cpp
+++ b/dom/base/nsDocument.cpp
@@ -386,8 +386,7 @@ nsIdentifierMapEntry::~nsIdentifierMapEntry()
 {}
 
 nsIdentifierMapEntry::nsIdentifierMapEntry(nsIdentifierMapEntry&& aOther)
-  : PLDHashEntryHdr(std::move(aOther))
-  , mKey(std::move(aOther.mKey))
+  : mKey(std::move(aOther.mKey))
   , mIdContentList(std::move(aOther.mIdContentList))
   , mNameContentList(std::move(aOther.mNameContentList))
   , mChangeCallbacks(std::move(aOther.mChangeCallbacks))
diff --git a/dom/base/nsIdentifierMapEntry.h b/dom/base/nsIdentifierMapEntry.h
index ce4f5fd1ead0..64a12525d2ad 100644
--- a/dom/base/nsIdentifierMapEntry.h
+++ b/dom/base/nsIdentifierMapEntry.h
@@ -182,9 +182,8 @@ public:
 
     explicit ChangeCallbackEntry(const ChangeCallback* aKey) :
       mKey(*aKey) { }
-    ChangeCallbackEntry(ChangeCallbackEntry&& aOther) :
-      PLDHashEntryHdr(std::move(aOther)),
-      mKey(std::move(aOther.mKey)) { }
+    ChangeCallbackEntry(const ChangeCallbackEntry& toCopy) :
+      mKey(toCopy.mKey) { }
 
     KeyType GetKey() const { return mKey; }
     bool KeyEquals(KeyTypePointer aKey) const {
diff --git a/dom/base/nsNodeInfoManager.h b/dom/base/nsNodeInfoManager.h
index 97fed1a16d98..876f900916cb 100644
--- a/dom/base/nsNodeInfoManager.h
+++ b/dom/base/nsNodeInfoManager.h
@@ -149,7 +149,6 @@ private:
   {
   public:
     explicit NodeInfoInnerKey(KeyTypePointer aKey) : nsPtrHashKey(aKey) {}
-    NodeInfoInnerKey(NodeInfoInnerKey&&) = default;
     ~NodeInfoInnerKey() = default;
     bool KeyEquals(KeyTypePointer aKey) const { return *mKey == *aKey; }
     static PLDHashNumber HashKey(KeyTypePointer aKey) { return aKey->Hash(); }
diff --git a/dom/commandhandler/nsCommandParams.cpp b/dom/commandhandler/nsCommandParams.cpp
index d72381c589a4..1a7258e06fef 100644
--- a/dom/commandhandler/nsCommandParams.cpp
+++ b/dom/commandhandler/nsCommandParams.cpp
@@ -336,10 +336,10 @@ nsCommandParams::HashMoveEntry(PLDHashTable* aTable,
                                const PLDHashEntryHdr* aFrom,
                                PLDHashEntryHdr* aTo)
 {
-  auto* fromEntry = const_cast<HashEntry*>(static_cast<const HashEntry*>(aFrom));
+  const HashEntry* fromEntry = static_cast<const HashEntry*>(aFrom);
   HashEntry* toEntry = static_cast<HashEntry*>(aTo);
 
-  new (KnownNotNull, toEntry) HashEntry(std::move(*fromEntry));
+  new (toEntry) HashEntry(*fromEntry);
 
   fromEntry->~HashEntry();
 }
diff --git a/dom/commandhandler/nsCommandParams.h b/dom/commandhandler/nsCommandParams.h
index 45c27c2d5061..befc4c8c8857 100644
--- a/dom/commandhandler/nsCommandParams.h
+++ b/dom/commandhandler/nsCommandParams.h
@@ -86,7 +86,7 @@ protected:
       Reset(mEntryType);
     }
 
-    explicit HashEntry(const HashEntry& aRHS)
+    HashEntry(const HashEntry& aRHS)
       : mEntryType(aRHS.mEntryType)
     {
       Reset(mEntryType);
diff --git a/dom/html/HTMLMediaElement.cpp b/dom/html/HTMLMediaElement.cpp
index d67ab3675df3..f9f317fb888c 100644
--- a/dom/html/HTMLMediaElement.cpp
+++ b/dom/html/HTMLMediaElement.cpp
@@ -3704,10 +3704,15 @@ HTMLMediaElement::MozCaptureStreamUntilEnded(ErrorResult& aRv)
 class MediaElementSetForURI : public nsURIHashKey
 {
 public:
-  explicit MediaElementSetForURI(const nsIURI* aKey) : nsURIHashKey(aKey) {}
-  MediaElementSetForURI(MediaElementSetForURI&& aOther)
-    : nsURIHashKey(std::move(aOther))
-    , mElements(std::move(aOther.mElements)) {}
+  explicit MediaElementSetForURI(const nsIURI* aKey)
+    : nsURIHashKey(aKey)
+  {
+  }
+  MediaElementSetForURI(const MediaElementSetForURI& toCopy)
+    : nsURIHashKey(toCopy)
+    , mElements(toCopy.mElements)
+  {
+  }
   nsTArray<HTMLMediaElement*> mElements;
 };
 
diff --git a/dom/smil/nsSMILCompositor.h b/dom/smil/nsSMILCompositor.h
index e8968a22e748..e1cddd104e86 100644
--- a/dom/smil/nsSMILCompositor.h
+++ b/dom/smil/nsSMILCompositor.h
@@ -35,8 +35,7 @@ public:
      mForceCompositing(false)
   { }
   nsSMILCompositor(nsSMILCompositor&& toMove)
-    : PLDHashEntryHdr(std::move(toMove)),
-      mKey(std::move(toMove.mKey)),
+    : mKey(std::move(toMove.mKey)),
       mAnimationFunctions(std::move(toMove.mAnimationFunctions)),
       mForceCompositing(false)
   { }
diff --git a/dom/storage/LocalStorageManager.h b/dom/storage/LocalStorageManager.h
index 6e76e282ab1c..d7b15f194958 100644
--- a/dom/storage/LocalStorageManager.h
+++ b/dom/storage/LocalStorageManager.h
@@ -66,10 +66,8 @@ private:
       , mCache(new LocalStorageCache(aKey))
     {}
 
-    LocalStorageCacheHashKey(LocalStorageCacheHashKey&& aOther)
-      : nsCStringHashKey(std::move(aOther))
-      , mCache(std::move(aOther.mCache))
-      , mCacheRef(std::move(aOther.mCacheRef))
+    LocalStorageCacheHashKey(const LocalStorageCacheHashKey& aOther)
+      : nsCStringHashKey(aOther)
     {
       NS_ERROR("Shouldn't be called");
     }
diff --git a/dom/xslt/xslt/txExecutionState.h b/dom/xslt/xslt/txExecutionState.h
index a3db0ccea472..1a2da00d4822 100644
--- a/dom/xslt/xslt/txExecutionState.h
+++ b/dom/xslt/xslt/txExecutionState.h
@@ -29,10 +29,8 @@ public:
                                                           mLoadResult(NS_OK)
     {
     }
-    txLoadedDocumentEntry(txLoadedDocumentEntry&& aOther)
-        : nsStringHashKey(std::move(aOther))
-        , mDocument(std::move(aOther.mDocument))
-        , mLoadResult(std::move(aOther.mLoadResult))
+    txLoadedDocumentEntry(const txLoadedDocumentEntry& aToCopy)
+        : nsStringHashKey(aToCopy)
     {
         NS_ERROR("We're horked.");
     }
diff --git a/gfx/thebes/gfxFontFeatures.h b/gfx/thebes/gfxFontFeatures.h
index 9d72a71969f5..83995173f0e6 100644
--- a/gfx/thebes/gfxFontFeatures.h
+++ b/gfx/thebes/gfxFontFeatures.h
@@ -112,10 +112,7 @@ private:
         typedef const FeatureValueHashKey *KeyTypePointer;
 
         explicit FeatureValueHashEntry(KeyTypePointer aKey) { }
-        FeatureValueHashEntry(FeatureValueHashEntry&& other)
-            : PLDHashEntryHdr(std::move(other))
-            , mKey(std::move(other.mKey))
-            , mValues(std::move(other.mValues))
+        FeatureValueHashEntry(const FeatureValueHashEntry& toCopy)
         {
             NS_ERROR("Should not be called");
         }
diff --git a/gfx/thebes/gfxGlyphExtents.h b/gfx/thebes/gfxGlyphExtents.h
index 1f5c5c16bf67..c4abb9c643db 100644
--- a/gfx/thebes/gfxGlyphExtents.h
+++ b/gfx/thebes/gfxGlyphExtents.h
@@ -89,7 +89,9 @@ private:
         // When constructing a new entry in the hashtable, we'll leave this
         // blank. The caller of Put() will fill this in.
         explicit HashEntry(KeyTypePointer aPtr) : nsUint32HashKey(aPtr) {}
-        HashEntry(HashEntry&& other) = default;
+        HashEntry(const HashEntry& toCopy) : nsUint32HashKey(toCopy) {
+          x = toCopy.x; y = toCopy.y; width = toCopy.width; height = toCopy.height;
+        }
 
         float x, y, width, height;
     };
diff --git a/gfx/thebes/gfxUserFontSet.h b/gfx/thebes/gfxUserFontSet.h
index 6fed0de2a8ed..35a36f3442f8 100644
--- a/gfx/thebes/gfxUserFontSet.h
+++ b/gfx/thebes/gfxUserFontSet.h
@@ -394,8 +394,7 @@ public:
             { }
 
             Entry(Entry&& aOther)
-                : PLDHashEntryHdr(std::move(aOther))
-                , mURI(std::move(aOther.mURI))
+                : mURI(std::move(aOther.mURI))
                 , mPrincipal(std::move(aOther.mPrincipal))
                 , mFontEntry(std::move(aOther.mFontEntry))
                 , mPrivate(std::move(aOther.mPrivate))
diff --git a/layout/painting/RetainedDisplayListHelpers.h b/layout/painting/RetainedDisplayListHelpers.h
index c7beca046d44..f34a44303cdf 100644
--- a/layout/painting/RetainedDisplayListHelpers.h
+++ b/layout/painting/RetainedDisplayListHelpers.h
@@ -28,7 +28,7 @@ public:
 
   explicit DisplayItemHashEntry(KeyTypePointer aKey)
     : mKey(*aKey) {}
-  DisplayItemHashEntry(DisplayItemHashEntry&&) = default;
+  explicit DisplayItemHashEntry(const DisplayItemHashEntry& aCopy)=default;
 
   ~DisplayItemHashEntry() = default;
 
diff --git a/layout/style/Loader.h b/layout/style/Loader.h
index 122c1baf8563..ff792018780b 100644
--- a/layout/style/Loader.h
+++ b/layout/style/Loader.h
@@ -24,7 +24,6 @@
 #include "mozilla/StyleSheetInlines.h"
 #include "mozilla/Maybe.h"
 #include "mozilla/MemoryReporting.h"
-#include "mozilla/Move.h"
 #include "mozilla/StyleSheet.h"
 #include "mozilla/UniquePtr.h"
 #include "mozilla/net/ReferrerPolicy.h"
@@ -70,11 +69,11 @@ public:
   {
     MOZ_COUNT_CTOR(URIPrincipalReferrerPolicyAndCORSModeHashKey);
   }
-  URIPrincipalReferrerPolicyAndCORSModeHashKey(URIPrincipalReferrerPolicyAndCORSModeHashKey&& toMove)
-    : nsURIHashKey(std::move(toMove)),
-      mPrincipal(std::move(toMove.mPrincipal)),
-      mCORSMode(std::move(toMove.mCORSMode)),
-      mReferrerPolicy(std::move(toMove.mReferrerPolicy))
+  URIPrincipalReferrerPolicyAndCORSModeHashKey(const URIPrincipalReferrerPolicyAndCORSModeHashKey& toCopy)
+    : nsURIHashKey(toCopy),
+      mPrincipal(toCopy.mPrincipal),
+      mCORSMode(toCopy.mCORSMode),
+      mReferrerPolicy(toCopy.mReferrerPolicy)
   {
     MOZ_COUNT_CTOR(URIPrincipalReferrerPolicyAndCORSModeHashKey);
   }
diff --git a/modules/libpref/Preferences.cpp b/modules/libpref/Preferences.cpp
index adf13125cbd5..065abe470ac9 100644
--- a/modules/libpref/Preferences.cpp
+++ b/modules/libpref/Preferences.cpp
@@ -2081,7 +2081,7 @@ public:
     mCanonical = canonical;
   }
 
-  // This is explicitly not a copy constructor.
+  // Copy constructor needs to be explicit or the linker complains.
   explicit PrefCallback(const PrefCallback*& aCopy)
     : mDomain(aCopy->mDomain)
     , mBranch(aCopy->mBranch)
@@ -2092,9 +2092,6 @@ public:
     MOZ_COUNT_CTOR(PrefCallback);
   }
 
-  PrefCallback(const PrefCallback&) = delete;
-  PrefCallback(PrefCallback&&) = default;
-
   ~PrefCallback() { MOZ_COUNT_DTOR(PrefCallback); }
 
   bool KeyEquals(const PrefCallback* aKey) const
diff --git a/netwerk/base/nsURIHashKey.h b/netwerk/base/nsURIHashKey.h
index 47994b953372..520d6c6faf37 100644
--- a/netwerk/base/nsURIHashKey.h
+++ b/netwerk/base/nsURIHashKey.h
@@ -9,7 +9,6 @@
 #include "nsCOMPtr.h"
 #include "nsIURI.h"
 #include "nsHashKeys.h"
-#include "mozilla/Move.h"
 #include "mozilla/Unused.h"
 
 /**
@@ -23,12 +22,8 @@ public:
 
     explicit nsURIHashKey(const nsIURI* aKey) :
         mKey(const_cast<nsIURI*>(aKey)) { MOZ_COUNT_CTOR(nsURIHashKey); }
-    nsURIHashKey(nsURIHashKey&& toMove)
-        : PLDHashEntryHdr(std::move(toMove))
-        , mKey(std::move(toMove.mKey))
-    {
-        MOZ_COUNT_CTOR(nsURIHashKey);
-    }
+    nsURIHashKey(const nsURIHashKey& toCopy) :
+        mKey(toCopy.mKey) { MOZ_COUNT_CTOR(nsURIHashKey); }
     ~nsURIHashKey() { MOZ_COUNT_DTOR(nsURIHashKey); }
 
     nsIURI* GetKey() const { return mKey; }
diff --git a/netwerk/cache/nsCacheEntry.cpp b/netwerk/cache/nsCacheEntry.cpp
index 613394a5d1f7..cfbad5201454 100644
--- a/netwerk/cache/nsCacheEntry.cpp
+++ b/netwerk/cache/nsCacheEntry.cpp
@@ -502,8 +502,8 @@ nsCacheEntryHashTable::MoveEntry(PLDHashTable * /* table */,
                                  const PLDHashEntryHdr *from,
                                  PLDHashEntryHdr       *to)
 {
-    new (KnownNotNull, to) nsCacheEntryHashTableEntry(std::move(*((nsCacheEntryHashTableEntry *)from)));
-    // No need to destroy `from`.
+    ((nsCacheEntryHashTableEntry *)to)->cacheEntry =
+        ((nsCacheEntryHashTableEntry *)from)->cacheEntry;
 }
 
 
diff --git a/netwerk/cache/nsDiskCacheBinding.cpp b/netwerk/cache/nsDiskCacheBinding.cpp
index 0f21f09d6446..3e3d92452616 100644
--- a/netwerk/cache/nsDiskCacheBinding.cpp
+++ b/netwerk/cache/nsDiskCacheBinding.cpp
@@ -43,8 +43,7 @@ MoveEntry(PLDHashTable *           /* table */,
           const PLDHashEntryHdr *     src,
           PLDHashEntryHdr       *     dst)
 {
-    new (KnownNotNull, dst) HashTableEntry(std::move(*(HashTableEntry*)src));
-    // No need to delete `src`.
+    ((HashTableEntry *)dst)->mBinding = ((HashTableEntry *)src)->mBinding;
 }
 
 
diff --git a/netwerk/cookie/nsCookieKey.h b/netwerk/cookie/nsCookieKey.h
index 098ed3e2a7ca..b716a9a0bab2 100644
--- a/netwerk/cookie/nsCookieKey.h
+++ b/netwerk/cookie/nsCookieKey.h
@@ -28,8 +28,10 @@ public:
     , mOriginAttributes(other->mOriginAttributes)
   {}
 
-  nsCookieKey(nsCookieKey&& other) = default;
-  nsCookieKey& operator=(nsCookieKey&&) = default;
+  nsCookieKey(KeyType other)
+    : mBaseDomain(other.mBaseDomain)
+    , mOriginAttributes(other.mOriginAttributes)
+  {}
 
   bool KeyEquals(KeyTypePointer other) const
   {
diff --git a/netwerk/cookie/nsCookieService.cpp b/netwerk/cookie/nsCookieService.cpp
index 694e670d1067..2478a3122d8b 100644
--- a/netwerk/cookie/nsCookieService.cpp
+++ b/netwerk/cookie/nsCookieService.cpp
@@ -2898,7 +2898,7 @@ nsCookieService::Read()
 
     nsCookieKey key(baseDomain, attrs);
     CookieDomainTuple* tuple = mReadArray.AppendElement();
-    tuple->key = std::move(key);
+    tuple->key = key;
     tuple->cookie = GetCookieFromRow(stmt, attrs);
   }
 
diff --git a/parser/html/nsHtml5AtomTable.cpp b/parser/html/nsHtml5AtomTable.cpp
index a21346637afc..958daea15dc8 100644
--- a/parser/html/nsHtml5AtomTable.cpp
+++ b/parser/html/nsHtml5AtomTable.cpp
@@ -11,8 +11,8 @@ nsHtml5AtomEntry::nsHtml5AtomEntry(KeyTypePointer aStr)
 {
 }
 
-nsHtml5AtomEntry::nsHtml5AtomEntry(nsHtml5AtomEntry&& aOther)
-  : nsStringHashKey(std::move(aOther))
+nsHtml5AtomEntry::nsHtml5AtomEntry(const nsHtml5AtomEntry& aOther)
+  : nsStringHashKey(aOther)
   , mAtom(nullptr)
 {
   MOZ_ASSERT_UNREACHABLE("nsHtml5AtomTable is broken; tried to copy an entry");
diff --git a/parser/html/nsHtml5AtomTable.h b/parser/html/nsHtml5AtomTable.h
index 2582ffdc2122..9ba15d7c8605 100644
--- a/parser/html/nsHtml5AtomTable.h
+++ b/parser/html/nsHtml5AtomTable.h
@@ -16,7 +16,7 @@ class nsHtml5AtomEntry : public nsStringHashKey
 {
 public:
   explicit nsHtml5AtomEntry(KeyTypePointer aStr);
-  nsHtml5AtomEntry(nsHtml5AtomEntry&& aOther);
+  nsHtml5AtomEntry(const nsHtml5AtomEntry& aOther);
   ~nsHtml5AtomEntry();
   inline nsAtom* GetAtom() { return mAtom; }
 
diff --git a/security/manager/ssl/nsCertOverrideService.h b/security/manager/ssl/nsCertOverrideService.h
index 9fe8d122821c..5a5ac9714496 100644
--- a/security/manager/ssl/nsCertOverrideService.h
+++ b/security/manager/ssl/nsCertOverrideService.h
@@ -81,8 +81,7 @@ class nsCertOverrideEntry final : public PLDHashEntryHdr
     }
 
     nsCertOverrideEntry(nsCertOverrideEntry&& toMove)
-      : PLDHashEntryHdr(std::move(toMove))
-      , mSettings(std::move(toMove.mSettings))
+      : mSettings(std::move(toMove.mSettings))
       , mHostWithPort(std::move(toMove.mHostWithPort))
     {
     }
diff --git a/security/manager/ssl/nsClientAuthRemember.h b/security/manager/ssl/nsClientAuthRemember.h
index 91be8c2b50a0..bfc6309204fb 100644
--- a/security/manager/ssl/nsClientAuthRemember.h
+++ b/security/manager/ssl/nsClientAuthRemember.h
@@ -65,8 +65,7 @@ class nsClientAuthRememberEntry final : public PLDHashEntryHdr
     }
 
     nsClientAuthRememberEntry(nsClientAuthRememberEntry&& aToMove)
-      : PLDHashEntryHdr(std::move(aToMove))
-      , mSettings(std::move(aToMove.mSettings))
+      : mSettings(std::move(aToMove.mSettings))
       , mEntryKey(std::move(aToMove.mEntryKey))
     {
     }
diff --git a/toolkit/components/places/History.h b/toolkit/components/places/History.h
index 0328c02f4faf..a052b259de6b 100644
--- a/toolkit/components/places/History.h
+++ b/toolkit/components/places/History.h
@@ -9,7 +9,6 @@
 
 #include "mozilla/IHistory.h"
 #include "mozilla/MemoryReporting.h"
-#include "mozilla/Move.h"
 #include "mozilla/Mutex.h"
 #include "mozIAsyncHistory.h"
 #include "nsIDownloadHistory.h"
@@ -213,10 +212,8 @@ private:
     : nsURIHashKey(aURI)
     {
     }
-    KeyClass(KeyClass&& aOther)
-      : nsURIHashKey(std::move(aOther))
-      , array(std::move(aOther.array))
-      , mVisited(std::move(aOther.mVisited))
+    KeyClass(const KeyClass& aOther)
+    : nsURIHashKey(aOther)
     {
       MOZ_ASSERT_UNREACHABLE("Do not call me!");
     }
@@ -240,7 +237,7 @@ private:
     explicit RecentURIKey(const nsIURI* aURI) : nsURIHashKey(aURI)
     {
     }
-    RecentURIKey(RecentURIKey&& aOther) : nsURIHashKey(std::move(aOther))
+    RecentURIKey(const RecentURIKey& aOther) : nsURIHashKey(aOther)
     {
       MOZ_ASSERT_UNREACHABLE("Do not call me!");
     }
diff --git a/toolkit/components/places/nsFaviconService.h b/toolkit/components/places/nsFaviconService.h
index d2703aead1c7..1b283988e1d1 100644
--- a/toolkit/components/places/nsFaviconService.h
+++ b/toolkit/components/places/nsFaviconService.h
@@ -21,7 +21,6 @@
 #include "imgITools.h"
 #include "mozilla/storage.h"
 #include "mozilla/Attributes.h"
-#include "mozilla/Move.h"
 
 #include "FaviconHelpers.h"
 
@@ -38,13 +37,11 @@ class UnassociatedIconHashKey : public nsURIHashKey
 {
 public:
   explicit UnassociatedIconHashKey(const nsIURI* aURI)
-    : nsURIHashKey(aURI)
+  : nsURIHashKey(aURI)
   {
   }
-  UnassociatedIconHashKey(UnassociatedIconHashKey&& aOther)
-    : nsURIHashKey(std::move(aOther))
-    , iconData(std::move(aOther.iconData))
-    , created(std::move(aOther.created))
+  UnassociatedIconHashKey(const UnassociatedIconHashKey& aOther)
+  : nsURIHashKey(aOther)
   {
     MOZ_ASSERT_UNREACHABLE("Do not call me!");
   }
diff --git a/toolkit/components/places/nsNavHistory.h b/toolkit/components/places/nsNavHistory.h
index 0d392e53ba62..618a1d9593b6 100644
--- a/toolkit/components/places/nsNavHistory.h
+++ b/toolkit/components/places/nsNavHistory.h
@@ -532,8 +532,8 @@ protected:
     : nsURIHashKey(aURI)
     {
     }
-    VisitHashKey(VisitHashKey&& aOther)
-      : nsURIHashKey(std::move(aOther))
+    VisitHashKey(const VisitHashKey& aOther)
+    : nsURIHashKey(aOther)
     {
       MOZ_ASSERT_UNREACHABLE("Do not call me!");
     }
diff --git a/toolkit/components/resistfingerprinting/nsRFPService.h b/toolkit/components/resistfingerprinting/nsRFPService.h
index c85caac6b754..ca5d89c81461 100644
--- a/toolkit/components/resistfingerprinting/nsRFPService.h
+++ b/toolkit/components/resistfingerprinting/nsRFPService.h
@@ -108,12 +108,11 @@ public:
     , mKey(aOther->mKey)
   {}
 
-  KeyboardHashKey(KeyboardHashKey&& aOther)
-    : PLDHashEntryHdr(std::move(aOther))
-    , mLang(std::move(aOther.mLang))
-    , mRegion(std::move(aOther.mRegion))
-    , mKeyIdx(std::move(aOther.mKeyIdx))
-    , mKey(std::move(aOther.mKey))
+  KeyboardHashKey(KeyType aOther)
+    : mLang(aOther.mLang)
+    , mRegion(aOther.mRegion)
+    , mKeyIdx(aOther.mKeyIdx)
+    , mKey(aOther.mKey)
   {}
 
   ~KeyboardHashKey()
diff --git a/xpcom/ds/PLDHashTable.h b/xpcom/ds/PLDHashTable.h
index a10ea77aab14..63bfadecff94 100644
--- a/xpcom/ds/PLDHashTable.h
+++ b/xpcom/ds/PLDHashTable.h
@@ -38,13 +38,6 @@ struct PLDHashTableOps;
 // -- users need never access it.
 struct PLDHashEntryHdr
 {
-  PLDHashEntryHdr() = default;
-  PLDHashEntryHdr(const PLDHashEntryHdr&) = delete;
-  PLDHashEntryHdr(const PLDHashEntryHdr&&) = delete;
-  PLDHashEntryHdr& operator=(const PLDHashEntryHdr&) = delete;
-  PLDHashEntryHdr(PLDHashEntryHdr&&) = default;
-  PLDHashEntryHdr& operator=(PLDHashEntryHdr&&) = default;
-
 private:
   friend class PLDHashTable;
 
diff --git a/xpcom/ds/nsHashKeys.h b/xpcom/ds/nsHashKeys.h
index 49f65d1cb0eb..795d8bda1303 100644
--- a/xpcom/ds/nsHashKeys.h
+++ b/xpcom/ds/nsHashKeys.h
@@ -24,9 +24,8 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include <utility>
-
 #include "mozilla/HashFunctions.h"
+#include "mozilla/Move.h"
 
 namespace mozilla {
 
@@ -82,11 +81,7 @@ public:
   typedef const nsAString* KeyTypePointer;
 
   explicit nsStringHashKey(KeyTypePointer aStr) : mStr(*aStr) {}
-  nsStringHashKey(const nsStringHashKey&) = delete;
-  nsStringHashKey(nsStringHashKey&& aToMove)
-    : PLDHashEntryHdr(std::move(aToMove))
-    , mStr(std::move(aToMove.mStr))
-  {}
+  nsStringHashKey(const nsStringHashKey& aToCopy) : mStr(aToCopy.mStr) {}
   ~nsStringHashKey() {}
 
   KeyType GetKey() const { return mStr; }
@@ -112,7 +107,7 @@ public:
   enum { ALLOW_MEMMOVE = true };
 
 private:
-  nsString mStr;
+  const nsString mStr;
 };
 
 #ifdef MOZILLA_INTERNAL_API
@@ -136,11 +131,8 @@ public:
   {
     // take it easy just deal HashKey
   }
-
-  nsStringCaseInsensitiveHashKey(const nsStringCaseInsensitiveHashKey&) = delete;
-  nsStringCaseInsensitiveHashKey(nsStringCaseInsensitiveHashKey&& aToMove)
-    : PLDHashEntryHdr(std::move(aToMove))
-    , mStr(std::move(aToMove.mStr))
+  nsStringCaseInsensitiveHashKey(const nsStringCaseInsensitiveHashKey& aToCopy)
+    : mStr(aToCopy.mStr)
   {
   }
   ~nsStringCaseInsensitiveHashKey() {}
@@ -184,10 +176,7 @@ public:
   typedef const nsACString* KeyTypePointer;
 
   explicit nsCStringHashKey(const nsACString* aStr) : mStr(*aStr) {}
-  nsCStringHashKey(nsCStringHashKey&& aOther)
-    : PLDHashEntryHdr(std::move(aOther))
-    , mStr(std::move(aOther.mStr))
-  {}
+  nsCStringHashKey(const nsCStringHashKey& aToCopy) : mStr(aToCopy.mStr) {}
   ~nsCStringHashKey() {}
 
   KeyType GetKey() const { return mStr; }
@@ -225,10 +214,7 @@ public:
   typedef const uint32_t* KeyTypePointer;
 
   explicit nsUint32HashKey(KeyTypePointer aKey) : mValue(*aKey) {}
-  nsUint32HashKey(nsUint32HashKey&& aOther)
-    : PLDHashEntryHdr(std::move(aOther))
-    , mValue(std::move(aOther.mValue))
-  {}
+  nsUint32HashKey(const nsUint32HashKey& aToCopy) : mValue(aToCopy.mValue) {}
   ~nsUint32HashKey() {}
 
   KeyType GetKey() const { return mValue; }
@@ -254,10 +240,7 @@ public:
   typedef const uint64_t* KeyTypePointer;
 
   explicit nsUint64HashKey(KeyTypePointer aKey) : mValue(*aKey) {}
-  nsUint64HashKey(nsUint64HashKey&& aOther)
-    : PLDHashEntryHdr(std::move(aOther))
-    , mValue(std::move(aOther.mValue))
-  {}
+  nsUint64HashKey(const nsUint64HashKey& aToCopy) : mValue(aToCopy.mValue) {}
   ~nsUint64HashKey() {}
 
   KeyType GetKey() const { return mValue; }
@@ -286,10 +269,7 @@ public:
   typedef const float* KeyTypePointer;
 
   explicit nsFloatHashKey(KeyTypePointer aKey) : mValue(*aKey) {}
-  nsFloatHashKey(nsFloatHashKey&& aOther)
-    : PLDHashEntryHdr(std::move(aOther))
-    , mValue(std::move(aOther.mValue))
-  {}
+  nsFloatHashKey(const nsFloatHashKey& aToCopy) : mValue(aToCopy.mValue) {}
   ~nsFloatHashKey() {}
 
   KeyType GetKey() const { return mValue; }
@@ -318,9 +298,7 @@ public:
   typedef const intptr_t* KeyTypePointer;
 
   explicit IntPtrHashKey(KeyTypePointer aKey) : mValue(*aKey) {}
-  IntPtrHashKey(IntPtrHashKey&& aOther)
-    : PLDHashEntryHdr(std::move(aOther))
-    , mValue(aOther.mValue) {}
+  IntPtrHashKey(const IntPtrHashKey& aToCopy) : mValue(aToCopy.mValue) {}
   ~IntPtrHashKey() {}
 
   KeyType GetKey() const { return mValue; }
@@ -352,9 +330,8 @@ public:
     : mSupports(const_cast<nsISupports*>(aKey))
   {
   }
-  nsISupportsHashKey(nsISupportsHashKey&& aOther)
-    : PLDHashEntryHdr(std::move(aOther))
-    , mSupports(std::move(aOther.mSupports))
+  nsISupportsHashKey(const nsISupportsHashKey& aToCopy)
+    : mSupports(aToCopy.mSupports)
   {
   }
   ~nsISupportsHashKey() {}
@@ -386,10 +363,7 @@ public:
   typedef const T* KeyTypePointer;
 
   explicit nsRefPtrHashKey(const T* aKey) : mKey(const_cast<T*>(aKey)) {}
-  nsRefPtrHashKey(nsRefPtrHashKey&& aOther)
-    : PLDHashEntryHdr(std::move(aOther))
-    , mKey(std::move(aOther.mKey))
-  {}
+  nsRefPtrHashKey(const nsRefPtrHashKey& aToCopy) : mKey(aToCopy.mKey) {}
   ~nsRefPtrHashKey() {}
 
   KeyType GetKey() const { return mKey; }
@@ -429,8 +403,8 @@ class nsClearingPtrHashKey : public nsPtrHashKey<T>
 {
 public:
   explicit nsClearingPtrHashKey(const T* aKey) : nsPtrHashKey<T>(aKey) {}
-  nsClearingPtrHashKey(nsClearingPtrHashKey&& aToMove)
-    : nsPtrHashKey<T>(std::move(aToMove))
+  nsClearingPtrHashKey(const nsClearingPtrHashKey<T>& aToCopy)
+    : nsPtrHashKey<T>(aToCopy)
   {
   }
   ~nsClearingPtrHashKey() { nsPtrHashKey<T>::mKey = nullptr; }
@@ -480,10 +454,7 @@ public:
   typedef const nsID* KeyTypePointer;
 
   explicit nsIDHashKey(const nsID* aInID) : mID(*aInID) {}
-  nsIDHashKey(nsIDHashKey&& aOther)
-    : PLDHashEntryHdr(std::move(aOther))
-    , mID(std::move(aOther.mID))
-  {}
+  nsIDHashKey(const nsIDHashKey& aToCopy) : mID(aToCopy.mID) {}
   ~nsIDHashKey() {}
 
   KeyType GetKey() const { return mID; }
@@ -499,7 +470,7 @@ public:
   enum { ALLOW_MEMMOVE = true };
 
 private:
-  nsID mID;
+  const nsID mID;
 };
 
 /**
@@ -514,9 +485,7 @@ public:
   typedef const nsID* KeyTypePointer;
 
   explicit nsIDPointerHashKey(const nsID* aInID) : mID(aInID) {}
-  nsIDPointerHashKey(nsIDPointerHashKey&& aOther)
-    : PLDHashEntryHdr(std::move(aOther))
-    , mID(aOther.mID) {}
+  nsIDPointerHashKey(const nsIDPointerHashKey& aToCopy) : mID(aToCopy.mID) {}
   ~nsIDPointerHashKey() = default;
 
   KeyType GetKey() const { return mID; }
@@ -552,10 +521,7 @@ public:
   typedef const char* KeyTypePointer;
 
   explicit nsDepCharHashKey(const char* aKey) : mKey(aKey) {}
-  nsDepCharHashKey(nsDepCharHashKey&& aOther)
-    : PLDHashEntryHdr(std::move(aOther))
-    , mKey(std::move(aOther.mKey))
-  {}
+  nsDepCharHashKey(const nsDepCharHashKey& aToCopy) : mKey(aToCopy.mKey) {}
   ~nsDepCharHashKey() {}
 
   const char* GetKey() const { return mKey; }
@@ -584,8 +550,11 @@ public:
   typedef const char* KeyTypePointer;
 
   explicit nsCharPtrHashKey(const char* aKey) : mKey(strdup(aKey)) {}
+  nsCharPtrHashKey(const nsCharPtrHashKey& aToCopy)
+    : mKey(strdup(aToCopy.mKey))
+  {
+  }
 
-  nsCharPtrHashKey(const nsCharPtrHashKey&) = delete;
   nsCharPtrHashKey(nsCharPtrHashKey&& aOther)
     : mKey(aOther.mKey)
   {
@@ -631,8 +600,11 @@ public:
   typedef const char16_t* KeyTypePointer;
 
   explicit nsUnicharPtrHashKey(const char16_t* aKey) : mKey(NS_strdup(aKey)) {}
+  nsUnicharPtrHashKey(const nsUnicharPtrHashKey& aToCopy)
+    : mKey(NS_strdup(aToCopy.mKey))
+  {
+  }
 
-  nsUnicharPtrHashKey(const nsUnicharPtrHashKey& aToCopy) = delete;
   nsUnicharPtrHashKey(nsUnicharPtrHashKey&& aOther)
     : mKey(aOther.mKey)
   {
@@ -679,10 +651,7 @@ public:
     : mKey(const_cast<nsIHashable*>(aKey))
   {
   }
-  nsHashableHashKey(nsHashableHashKey&& aOther)
-    : PLDHashEntryHdr(std::move(aOther))
-    , mKey(std::move(aOther.mKey))
-  {}
+  nsHashableHashKey(const nsHashableHashKey& aToCopy) : mKey(aToCopy.mKey) {}
   ~nsHashableHashKey() {}
 
   nsIHashable* GetKey() const { return mKey; }
@@ -737,10 +706,7 @@ public:
   typedef const T* KeyTypePointer;
 
   explicit nsGenericHashKey(KeyTypePointer aKey) : mKey(*aKey) {}
-  nsGenericHashKey(const nsGenericHashKey&) = delete;
-  nsGenericHashKey(nsGenericHashKey&& aOther)
-    : PLDHashEntryHdr(std::move(aOther))
-    , mKey(std::move(aOther.mKey)) {}
+  nsGenericHashKey(const nsGenericHashKey<T>& aOther) : mKey(aOther.mKey) {}
 
   KeyType GetKey() const { return mKey; }
   bool KeyEquals(KeyTypePointer aKey) const { return *aKey == mKey; }
diff --git a/xpcom/ds/nsObserverList.h b/xpcom/ds/nsObserverList.h
index 286b60b35c3f..90a685ea60d8 100644
--- a/xpcom/ds/nsObserverList.h
+++ b/xpcom/ds/nsObserverList.h
@@ -51,12 +51,6 @@ public:
     MOZ_COUNT_CTOR(nsObserverList);
   }
 
-  nsObserverList(nsObserverList&& aOther)
-    : nsCharPtrHashKey(std::move(aOther))
-    , mObservers(std::move(aOther.mObservers))
-  {
-  }
-
   ~nsObserverList()
   {
     MOZ_COUNT_DTOR(nsObserverList);
diff --git a/xpcom/ds/nsPointerHashKeys.h b/xpcom/ds/nsPointerHashKeys.h
index 88e35116e4f2..1d3f2d3d695d 100644
--- a/xpcom/ds/nsPointerHashKeys.h
+++ b/xpcom/ds/nsPointerHashKeys.h
@@ -27,10 +27,7 @@ public:
   typedef const T* KeyTypePointer;
 
   explicit nsPtrHashKey(const T* aKey) : mKey(const_cast<T*>(aKey)) {}
-  nsPtrHashKey(nsPtrHashKey<T>&& aToMove)
-    : PLDHashEntryHdr(std::move(aToMove))
-    , mKey(std::move(aToMove.mKey))
-  {}
+  nsPtrHashKey(const nsPtrHashKey<T>& aToCopy) : mKey(aToCopy.mKey) {}
   ~nsPtrHashKey() {}
 
   KeyType GetKey() const { return mKey; }