diff --git a/mfbt/DefineEnum.h b/mfbt/DefineEnum.h
index afcff10e5212..a195c840229c 100644
--- a/mfbt/DefineEnum.h
+++ b/mfbt/DefineEnum.h
@@ -10,6 +10,7 @@
 #define mozilla_DefineEnum_h
 
 #include <stddef.h>  // for size_t
+#include <ostream>   // for std::ostream
 
 #include "mozilla/MacroArgs.h"     // for MOZ_ARG_COUNT
 #include "mozilla/MacroForEach.h"  // for MOZ_FOR_EACH
@@ -84,6 +85,14 @@
  *      and have names prefixed with "s" instead of "k" as per
  *      naming convention.
  *
+ *    - A |_TOSTRING| variant, which generates an EnumValueToString function,
+ *      converting the enum items to strings, and implements an "operator<<",
+ *      providing a consistent way to convert enums to strings by
+ *      mozilla::ToString function regardless of their definition context.
+ *      For users needing C-string compatibility for logging in restricted
+ *      contexts or performance sensitive applications, EnumValueToString is
+ *      preferred.
+ *
  *  (and combinations of these).
  */
 
@@ -153,4 +162,58 @@
   MOZ_DEFINE_ENUM_AT_CLASS_SCOPE_IMPL(aEnumName, class,                      \
                                       : aBaseName, aEnumerators)
 
+#define MOZ_DEFINE_ENUM_TO_ENUM_TEXT(aEnumeratorDecl) #aEnumeratorDecl
+
+#define MOZ_DEFINE_ENUM_TOSTRING_FUNC_IMPL(aEnumName, aEnumerators, aFriend) \
+  inline static const char* EnumValueToString(const aEnumName& aEnum) {      \
+    static constexpr const char* kMappedStrings[] = {MOZ_FOR_EACH_SEPARATED( \
+        MOZ_DEFINE_ENUM_TO_ENUM_TEXT, (, ), (), aEnumerators)};              \
+    return kMappedStrings[static_cast<size_t>(aEnum)];                       \
+  }                                                                          \
+  aFriend inline std::ostream& operator<<(std::ostream& aStream,             \
+                                          const aEnumName& aEnum) {          \
+    aStream << EnumValueToString(aEnum);                                     \
+    return aStream;                                                          \
+  }
+
+#define MOZ_DEFINE_ENUM_TOSTRING_FUNC(aEnumName, aEnumerators) \
+  MOZ_DEFINE_ENUM_TOSTRING_FUNC_IMPL(aEnumName, aEnumerators, )
+
+#define MOZ_DEFINE_ENUM_TOSTRING_FUNC_IN_CLASS(aEnumName, aEnumerators) \
+  MOZ_DEFINE_ENUM_TOSTRING_FUNC_IMPL(aEnumName, aEnumerators, friend)
+
+#define MOZ_DEFINE_ENUM_WITH_BASE_AND_TOSTRING(aEnumName, aBaseName, \
+                                               aEnumerators)         \
+  MOZ_DEFINE_ENUM_WITH_BASE(aEnumName, aBaseName, aEnumerators)      \
+  MOZ_DEFINE_ENUM_TOSTRING_FUNC(aEnumName, aEnumerators)
+
+#define MOZ_DEFINE_ENUM_CLASS_WITH_TOSTRING(aEnumName, aEnumerators) \
+  MOZ_DEFINE_ENUM_CLASS(aEnumName, aEnumerators)                     \
+  MOZ_DEFINE_ENUM_TOSTRING_FUNC(aEnumName, aEnumerators)
+
+#define MOZ_DEFINE_ENUM_CLASS_WITH_BASE_AND_TOSTRING(aEnumName, aBaseName, \
+                                                     aEnumerators)         \
+  MOZ_DEFINE_ENUM_CLASS_WITH_BASE(aEnumName, aBaseName, aEnumerators)      \
+  MOZ_DEFINE_ENUM_TOSTRING_FUNC(aEnumName, aEnumerators)
+
+#define MOZ_DEFINE_ENUM_WITH_TOSTRING_AT_CLASS_SCOPE(aEnumName, aEnumerators) \
+  MOZ_DEFINE_ENUM_AT_CLASS_SCOPE(aEnumName, aEnumerators)                     \
+  MOZ_DEFINE_ENUM_TOSTRING_FUNC_IN_CLASS(aEnumName, aEnumerators)
+
+#define MOZ_DEFINE_ENUM_WITH_BASE_AND_TOSTRING_AT_CLASS_SCOPE(                 \
+    aEnumName, aBaseName, aEnumerators)                                        \
+  MOZ_DEFINE_ENUM_WITH_BASE_AT_CLASS_SCOPE(aEnumName, aBaseName, aEnumerators) \
+  MOZ_DEFINE_ENUM_TOSTRING_FUNC_IN_CLASS(aEnumName, aEnumerators)
+
+#define MOZ_DEFINE_ENUM_CLASS_WITH_TOSTRING_AT_CLASS_SCOPE(aEnumName,    \
+                                                           aEnumerators) \
+  MOZ_DEFINE_ENUM_CLASS_AT_CLASS_SCOPE(aEnumName, aEnumerators)          \
+  MOZ_DEFINE_ENUM_TOSTRING_FUNC_IN_CLASS(aEnumName, aEnumerators)
+
+#define MOZ_DEFINE_ENUM_CLASS_WITH_BASE_AND_TOSTRING_AT_CLASS_SCOPE(   \
+    aEnumName, aBaseName, aEnumerators)                                \
+  MOZ_DEFINE_ENUM_CLASS_WITH_BASE_AT_CLASS_SCOPE(aEnumName, aBaseName, \
+                                                 aEnumerators)         \
+  MOZ_DEFINE_ENUM_TOSTRING_FUNC_IN_CLASS(aEnumName, aEnumerators)
+
 #endif  // mozilla_DefineEnum_h