--- core/fxcrt/fx_memory_wrappers.h
+++ core/fxcrt/fx_memory_wrappers.h
@@ -70,8 +70,8 @@
   }
 
   // There's no state, so they are all the same,
-  bool operator==(const FxAllocAllocator& that) { return true; }
-  bool operator!=(const FxAllocAllocator& that) { return false; }
+  bool operator==(const FxAllocAllocator& that) const { return true; }
+  bool operator!=(const FxAllocAllocator& that) const { return false; }
 };
 
 #endif  // CORE_FXCRT_FX_MEMORY_WRAPPERS_H_