diff --git a/dynamic.c b/dynamic.c
index c74bb92c04..b2ad6bb394 100644
--- a/dynamic.c
+++ b/dynamic.c
@@ -1609,7 +1609,16 @@ bool rarch_environment_cb(unsigned cmd, void *data)
       }
 
       case RETRO_ENVIRONMENT_SET_SERIALIZATION_QUIRKS:
-         core_set_serialization_quirks(*((uint32_t *) data));
+         core_set_serialization_quirks(*((uint64_t *) data));
+
+         /* Zero any unrecognized quirks */
+         *((uint64_t *) data) &= ~((uint64_t)
+         ((RETRO_SERIALIZATION_QUIRK_ARCHITECTURE_DEPENDENT-1) |
+           RETRO_SERIALIZATION_QUIRK_ARCHITECTURE_DEPENDENT));
+
+         /* And zero variable-sized serialization, which we don't support */
+         *((uint64_t *) data) &= ~((uint64_t) RETRO_SERIALIZATION_QUIRK_VARIABLE_SIZE);
+
          break;
 
       /* Default */
diff --git a/libretro-common/include/libretro.h b/libretro-common/include/libretro.h
index e1a3c46e71..7f8e340aa5 100644
--- a/libretro-common/include/libretro.h
+++ b/libretro-common/include/libretro.h
@@ -997,7 +997,8 @@ struct retro_hw_render_context_negotiation_interface
 
 #define RETRO_ENVIRONMENT_SET_SERIALIZATION_QUIRKS 44
                                            /* uint64_t * --
-                                            * Sets quirk flags associated with serialization.
+                                            * Sets quirk flags associated with serialization. The frontend will zero any flags it doesn't
+                                            * recognize or support.
                                             */