diff --git a/browser/app/macbuild/Contents/MacOS-files.in b/browser/app/macbuild/Contents/MacOS-files.in
index 8c43996f34b9..f43118ba8879 100644
--- a/browser/app/macbuild/Contents/MacOS-files.in
+++ b/browser/app/macbuild/Contents/MacOS-files.in
@@ -10,7 +10,7 @@
 #endif
 /gtest/***
 /http3server
-#if defined(MOZ_ASAN) || defined(MOZ_TSAN)
+#if defined(MOZ_ASAN) || defined(MOZ_TSAN) || defined(FUZZING)
 /llvm-symbolizer
 #endif
 #if defined(MOZ_CRASHREPORTER)
diff --git a/browser/app/macbuild/Contents/moz.build b/browser/app/macbuild/Contents/moz.build
index b8b28926de46..88c7651dee7d 100644
--- a/browser/app/macbuild/Contents/moz.build
+++ b/browser/app/macbuild/Contents/moz.build
@@ -10,6 +10,7 @@ for s in (
     "MOZ_GECKODRIVER",
     "MOZ_ASAN",
     "MOZ_TSAN",
+    "FUZZING",
     "MOZ_CRASHREPORTER",
     "MOZ_APP_NAME",
 ):
diff --git a/browser/config/mozconfigs/macosx64/debug-fuzzing b/browser/config/mozconfigs/macosx64/debug-fuzzing
index 9a5b2402f545..155f1319f144 100644
--- a/browser/config/mozconfigs/macosx64/debug-fuzzing
+++ b/browser/config/mozconfigs/macosx64/debug-fuzzing
@@ -6,4 +6,6 @@ ac_add_options --enable-fuzzing
 # Need this to prevent name conflicts with the normal nightly build packages
 export MOZ_PKG_SPECIAL=fuzzing
 
+export LLVM_SYMBOLIZER="$MOZ_FETCHES_DIR/llvm-symbolizer/bin/llvm-symbolizer"
+
 . "$topsrcdir/build/mozconfig.common.override"
diff --git a/build/autoconf/sanitize.m4 b/build/autoconf/sanitize.m4
index becdf0295d9d..07dc86bc41e2 100644
--- a/build/autoconf/sanitize.m4
+++ b/build/autoconf/sanitize.m4
@@ -40,10 +40,7 @@ if test -n "$MOZ_ASAN"; then
     if test -z "$CLANG_CL"; then
         LDFLAGS="-fsanitize=address -rdynamic $LDFLAGS"
     fi
-    AC_DEFINE(MOZ_ASAN)
-    MOZ_PATH_PROG(LLVM_SYMBOLIZER, llvm-symbolizer)
 fi
-AC_SUBST(MOZ_ASAN)
 
 dnl ========================================================
 dnl = Use Memory Sanitizer
@@ -54,10 +51,7 @@ if test -n "$MOZ_MSAN"; then
     if test -z "$CLANG_CL"; then
         LDFLAGS="-fsanitize=memory -fsanitize-memory-track-origins -rdynamic $LDFLAGS"
     fi
-    AC_DEFINE(MOZ_MSAN)
-    MOZ_PATH_PROG(LLVM_SYMBOLIZER, llvm-symbolizer)
 fi
-AC_SUBST(MOZ_MSAN)
 
 dnl ========================================================
 dnl = Use Thread Sanitizer
@@ -68,16 +62,12 @@ if test -n "$MOZ_TSAN"; then
     if test -z "$CLANG_CL"; then
         LDFLAGS="-fsanitize=thread -rdynamic $LDFLAGS"
     fi
-    AC_DEFINE(MOZ_TSAN)
-    MOZ_PATH_PROG(LLVM_SYMBOLIZER, llvm-symbolizer)
 fi
-AC_SUBST(MOZ_TSAN)
 
 dnl ========================================================
 dnl = Use UndefinedBehavior Sanitizer (with custom checks)
 dnl ========================================================
 if test -n "$MOZ_UBSAN_CHECKS"; then
-    MOZ_UBSAN=1
     UBSAN_TXT="$_objdir/ubsan_blacklist.txt"
     cat $_topsrcdir/build/sanitizers/ubsan_*_blacklist.txt > $UBSAN_TXT
     UBSAN_FLAGS="-fsanitize=$MOZ_UBSAN_CHECKS -fno-sanitize-recover=$MOZ_UBSAN_CHECKS -fsanitize-blacklist=$UBSAN_TXT"
@@ -86,16 +76,12 @@ if test -n "$MOZ_UBSAN_CHECKS"; then
     if test -z "$CLANG_CL"; then
         LDFLAGS="-fsanitize=undefined -rdynamic $LDFLAGS"
     fi
-    AC_DEFINE(MOZ_UBSAN)
-    MOZ_PATH_PROG(LLVM_SYMBOLIZER, llvm-symbolizer)
 fi
-AC_SUBST(MOZ_UBSAN)
 
 dnl ========================================================
 dnl = Use UndefinedBehavior Sanitizer to find integer overflows
 dnl ========================================================
 if test -n "$MOZ_SIGNED_OVERFLOW_SANITIZE$MOZ_UNSIGNED_OVERFLOW_SANITIZE"; then
-    MOZ_UBSAN=1
     SANITIZER_BLACKLISTS=""
     if test -n "$MOZ_SIGNED_OVERFLOW_SANITIZE"; then
         SANITIZER_BLACKLISTS="-fsanitize-blacklist=$_topsrcdir/build/sanitizers/ubsan_signed_overflow_blacklist.txt $SANITIZER_BLACKLISTS"
@@ -104,7 +90,6 @@ if test -n "$MOZ_SIGNED_OVERFLOW_SANITIZE$MOZ_UNSIGNED_OVERFLOW_SANITIZE"; then
         if test -z "$CLANG_CL"; then
             LDFLAGS="-fsanitize=signed-integer-overflow -rdynamic $LDFLAGS"
         fi
-        AC_DEFINE(MOZ_SIGNED_OVERFLOW_SANITIZE)
     fi
     if test -n "$MOZ_UNSIGNED_OVERFLOW_SANITIZE"; then
         SANITIZER_BLACKLISTS="-fsanitize-blacklist=$_topsrcdir/build/sanitizers/ubsan_unsigned_overflow_blacklist.txt $SANITIZER_BLACKLISTS"
@@ -113,16 +98,10 @@ if test -n "$MOZ_SIGNED_OVERFLOW_SANITIZE$MOZ_UNSIGNED_OVERFLOW_SANITIZE"; then
         if test -z "$CLANG_CL"; then
             LDFLAGS="-fsanitize=unsigned-integer-overflow -rdynamic $LDFLAGS"
         fi
-        AC_DEFINE(MOZ_UNSIGNED_OVERFLOW_SANITIZE)
     fi
     CFLAGS="$SANITIZER_BLACKLISTS $CFLAGS"
     CXXFLAGS="$SANITIZER_BLACKLISTS $CXXFLAGS"
-    AC_DEFINE(MOZ_UBSAN)
-    MOZ_PATH_PROG(LLVM_SYMBOLIZER, llvm-symbolizer)
 fi
-AC_SUBST(MOZ_SIGNED_OVERFLOW_SANITIZE)
-AC_SUBST(MOZ_UNSIGNED_OVERFLOW_SANITIZE)
-AC_SUBST(MOZ_UBSAN)
 
 dnl =======================================================
 dnl = Required for stand-alone (sanitizer-less) libFuzzer.
@@ -131,9 +110,6 @@ if test -n "$LIBFUZZER"; then
    LDFLAGS="$LIBFUZZER_FLAGS -rdynamic $LDFLAGS"
 fi
 
-# The LLVM symbolizer is used by all sanitizers
-AC_SUBST(LLVM_SYMBOLIZER)
-
 dnl ========================================================
 dnl = Test for whether the compiler is compatible with the
 dnl = given sanitize options.
diff --git a/build/moz.configure/toolchain.configure b/build/moz.configure/toolchain.configure
index 9e9ae2657803..dedcd7518366 100644
--- a/build/moz.configure/toolchain.configure
+++ b/build/moz.configure/toolchain.configure
@@ -2429,6 +2429,8 @@ def asan():
 
 
 add_old_configure_assignment("MOZ_ASAN", asan)
+set_define("MOZ_ASAN", True, when=asan)
+set_config("MOZ_ASAN", True, when=asan)
 
 # MSAN
 # ==============================================================
@@ -2442,6 +2444,8 @@ def msan():
 
 
 add_old_configure_assignment("MOZ_MSAN", msan)
+set_define("MOZ_MSAN", True, when=msan)
+set_config("MOZ_MSAN", True, when=msan)
 
 # TSAN
 # ==============================================================
@@ -2455,6 +2459,8 @@ def tsan():
 
 
 add_old_configure_assignment("MOZ_TSAN", tsan)
+set_define("MOZ_TSAN", True, when=tsan)
+set_config("MOZ_TSAN", True, when=tsan)
 
 # UBSAN
 # ==============================================================
@@ -2491,7 +2497,6 @@ def ubsan(options, optimize):
 
 add_old_configure_assignment("MOZ_UBSAN_CHECKS", ubsan)
 
-
 option(
     "--enable-signed-overflow-sanitizer",
     help="Enable UndefinedBehavior Sanitizer (Signed Integer Overflow Parts)",
@@ -2504,6 +2509,8 @@ def ub_signed_overflow_san():
 
 
 add_old_configure_assignment("MOZ_SIGNED_OVERFLOW_SANITIZE", ub_signed_overflow_san)
+set_define("MOZ_SIGNED_OVERFLOW_SANITIZE", True, when=ub_signed_overflow_san)
+set_config("MOZ_SIGNED_OVERFLOW_SANITIZE", True, when=ub_signed_overflow_san)
 
 
 option(
@@ -2518,7 +2525,14 @@ def ub_unsigned_overflow_san():
 
 
 add_old_configure_assignment("MOZ_UNSIGNED_OVERFLOW_SANITIZE", ub_unsigned_overflow_san)
+set_define("MOZ_UNSIGNED_OVERFLOW_SANITIZE", True, when=ub_unsigned_overflow_san)
+set_config("MOZ_UNSIGNED_OVERFLOW_SANITIZE", True, when=ub_unsigned_overflow_san)
 
+#
+
+any_ubsan = ubsan | ub_signed_overflow_san | ub_unsigned_overflow_san
+set_define("MOZ_UBSAN", True, when=any_ubsan)
+set_config("MOZ_UBSAN", any_ubsan)
 
 # Security Hardening
 # ==============================================================
@@ -3122,6 +3136,16 @@ set_config("HAVE_LIBFUZZER_FLAG_FUZZER_NO_LINK", libfuzzer_flags.no_link_flag_su
 set_config("LIBFUZZER_FLAGS", libfuzzer_flags.use_flags)
 add_old_configure_assignment("LIBFUZZER_FLAGS", libfuzzer_flags.use_flags)
 
+# The LLVM symbolizer is used by all sanitizers
+check_prog(
+    "LLVM_SYMBOLIZER",
+    ("llvm-symbolizer",),
+    allow_missing=True,
+    paths=clang_search_path,
+    when=asan | msan | tsan | any_ubsan | enable_fuzzing,
+)
+
+
 # Shared library building
 # ==============================================================
 
diff --git a/mobile/android/config/mozconfigs/android-x86_64/nightly-fuzzing-asan b/mobile/android/config/mozconfigs/android-x86_64/nightly-fuzzing-asan
index 63467dafb210..6d00e50a0ba3 100644
--- a/mobile/android/config/mozconfigs/android-x86_64/nightly-fuzzing-asan
+++ b/mobile/android/config/mozconfigs/android-x86_64/nightly-fuzzing-asan
@@ -15,6 +15,9 @@ ac_add_options --enable-fuzzing
 unset MOZ_STDCXX_COMPAT
 unset ENABLE_CLANG_PLUGIN
 
+# We don't have a native LLVM_SYMBOLIZER yet
+unset LLVM_SYMBOLIZER
+
 # Add the path to the clang_rt used, so it can be packaged with the build.
 if [ -d "$MOZ_FETCHES_DIR/clang" ]; then
     CLANG_LIB_DIR="$(cd $MOZ_FETCHES_DIR/clang/lib/clang/*/lib/linux && pwd)"
diff --git a/taskcluster/kinds/build/macosx.yml b/taskcluster/kinds/build/macosx.yml
index b4bcb7e20548..c9e3bd78a98a 100644
--- a/taskcluster/kinds/build/macosx.yml
+++ b/taskcluster/kinds/build/macosx.yml
@@ -201,6 +201,7 @@ macosx64-fuzzing/debug:
             - linux64-clang
             - linux64-sccache
             - macosx64-sdk
+            - macosx64-llvm-symbolizer
             - sysroot-wasm32-wasi
     optimization:
         skip-unless-expanded: null