diff --git a/memory/mozalloc/mozalloc.h b/memory/mozalloc/mozalloc.h
index 2b370ec25229..a1479ad48997 100644
--- a/memory/mozalloc/mozalloc.h
+++ b/memory/mozalloc/mozalloc.h
@@ -203,7 +203,13 @@ MOZALLOC_EXPORT void* moz_valloc(size_t size)
 
 #define MOZALLOC_THROW_BAD_ALLOC MOZALLOC_THROW_BAD_ALLOC_IF_HAS_EXCEPTIONS
 
-MOZALLOC_EXPORT_NEW MOZALLOC_INLINE
+MOZALLOC_EXPORT_NEW
+#if defined(__GNUC__) && !defined(__clang__) && defined(__SANITIZE_ADDRESS__)
+/* gcc's asan somehow doesn't like always_inline on this function. */
+__attribute__((gnu_inline)) inline
+#else
+MOZALLOC_INLINE
+#endif
 void* operator new(size_t size) MOZALLOC_THROW_BAD_ALLOC
 {
     return moz_xmalloc(size);