diff --git a/accessible/interfaces/ia2/moz.build b/accessible/interfaces/ia2/moz.build
index 5ba924822d5e..da3d1d39b058 100644
--- a/accessible/interfaces/ia2/moz.build
+++ b/accessible/interfaces/ia2/moz.build
@@ -98,6 +98,3 @@ if CONFIG['CC_TYPE'] == 'clang-cl':
         '-Wno-missing-braces',
         '-Wno-unused-const-variable',
     ]
-
-if CONFIG['MOZ_PGO'] and CONFIG['CC_TYPE'] == 'clang-cl':
-    AllowCompilerWarnings()  # workaround for bug 1090497
diff --git a/accessible/interfaces/msaa/moz.build b/accessible/interfaces/msaa/moz.build
index 2eb59bff56ce..14aabb852e2f 100644
--- a/accessible/interfaces/msaa/moz.build
+++ b/accessible/interfaces/msaa/moz.build
@@ -44,6 +44,3 @@ if CONFIG['CC_TYPE'] == 'clang-cl':
         '-Wno-missing-braces',
         '-Wno-unused-const-variable',
     ]
-
-if CONFIG['MOZ_PGO'] and CONFIG['CC_TYPE'] == 'clang-cl':
-    AllowCompilerWarnings()  # workaround for bug 1090497
diff --git a/build/moz.configure/toolchain.configure b/build/moz.configure/toolchain.configure
index 3b564eb2043b..9cdbf7c859ed 100755
--- a/build/moz.configure/toolchain.configure
+++ b/build/moz.configure/toolchain.configure
@@ -1267,6 +1267,7 @@ def pgo_flags(compiler, build_env, target):
               gen_cflags=['-fprofile-instr-generate'],
               gen_ldflags=['clang_rt.profile-x86_64.lib'],
               use_cflags=['-fprofile-instr-use=%s' % profdata,
+                          '-Wno-error=profile-instr-out-of-date',
                           '-Wno-error=profile-instr-unprofiled'],
               use_ldflags=[],
           )
diff --git a/dom/plugins/ipc/hangui/moz.build b/dom/plugins/ipc/hangui/moz.build
index bf6583ea3c44..b5fd3e37c8eb 100644
--- a/dom/plugins/ipc/hangui/moz.build
+++ b/dom/plugins/ipc/hangui/moz.build
@@ -26,7 +26,6 @@ OS_LIBS += [
     'comctl32',
 ]
 
-if ((CONFIG['MOZ_PGO'] or
-     (not CONFIG['HAVE_64BIT_BUILD'] and CONFIG['ENABLE_CLANG_PLUGIN']))
+if (not CONFIG['HAVE_64BIT_BUILD'] and CONFIG['ENABLE_CLANG_PLUGIN']
     and CONFIG['CC_TYPE'] == 'clang-cl'):
     AllowCompilerWarnings()  # workaround for bug 1090497
diff --git a/dom/url/moz.build b/dom/url/moz.build
index 45d33a449295..2c8545912907 100644
--- a/dom/url/moz.build
+++ b/dom/url/moz.build
@@ -30,6 +30,3 @@ BROWSER_CHROME_MANIFESTS += [ 'tests/browser.ini' ]
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
-
-if CONFIG['MOZ_PGO'] and CONFIG['CC_TYPE'] == 'clang-cl':
-    AllowCompilerWarnings()  # workaround for bug 1090497
diff --git a/ipc/contentproc/moz.build b/ipc/contentproc/moz.build
index 10e80926af53..07cf0b97c676 100644
--- a/ipc/contentproc/moz.build
+++ b/ipc/contentproc/moz.build
@@ -23,6 +23,3 @@ if CONFIG['MOZ_SANDBOX'] and CONFIG['OS_ARCH'] == 'WINNT':
         '/security/sandbox/chromium',
         '/security/sandbox/chromium-shim',
     ]
-
-if CONFIG['MOZ_PGO'] and CONFIG['CC_TYPE'] == 'clang-cl':
-    AllowCompilerWarnings()  # workaround for bug 1090497
diff --git a/js/xpconnect/shell/moz.build b/js/xpconnect/shell/moz.build
index 16d68399e6ca..c9f1137bdab5 100644
--- a/js/xpconnect/shell/moz.build
+++ b/js/xpconnect/shell/moz.build
@@ -53,6 +53,3 @@ if CONFIG['OS_ARCH'] == 'WINNT':
 CFLAGS += CONFIG['TK_CFLAGS']
 CXXFLAGS += CONFIG['TK_CFLAGS']
 OS_LIBS += CONFIG['TK_LIBS']
-
-if CONFIG['MOZ_PGO'] and CONFIG['CC_TYPE'] == 'clang-cl':
-    AllowCompilerWarnings()  # workaround for bug 1090497
diff --git a/mozglue/tests/gtest/InjectorDLL/moz.build b/mozglue/tests/gtest/InjectorDLL/moz.build
index 053221dd61b6..9f60e9443373 100644
--- a/mozglue/tests/gtest/InjectorDLL/moz.build
+++ b/mozglue/tests/gtest/InjectorDLL/moz.build
@@ -13,6 +13,3 @@ UNIFIED_SOURCES = [
 
 if CONFIG['COMPILE_ENVIRONMENT']:
     TEST_HARNESS_FILES.gtest += ['!InjectorDLL.dll']
-
-if CONFIG['MOZ_PGO'] and CONFIG['CC_TYPE'] == 'clang-cl':
-    AllowCompilerWarnings()  # workaround for bug 1090497
diff --git a/toolkit/crashreporter/minidump-analyzer/moz.build b/toolkit/crashreporter/minidump-analyzer/moz.build
index 3df941ee8493..70f3b259a9d8 100644
--- a/toolkit/crashreporter/minidump-analyzer/moz.build
+++ b/toolkit/crashreporter/minidump-analyzer/moz.build
@@ -59,6 +59,3 @@ if CONFIG['OS_TARGET'] != 'WINNT':
     DisableStlWrapping()
 
 include('/toolkit/crashreporter/crashreporter.mozbuild')
-
-if CONFIG['MOZ_PGO'] and CONFIG['CC_TYPE'] == 'clang-cl':
-    AllowCompilerWarnings()  # workaround for bug 1090497