diff --git a/src/Core/Resource/Script/Property/CFlagsProperty.cpp b/src/Core/Resource/Script/Property/CFlagsProperty.cpp
index bd60f973..cd899a30 100644
--- a/src/Core/Resource/Script/Property/CFlagsProperty.cpp
+++ b/src/Core/Resource/Script/Property/CFlagsProperty.cpp
@@ -46,7 +46,7 @@ TString CFlagsProperty::ValueAsString(void* pData) const
  * Checks whether there are any unrecognized bits toggled on in the property value.
  * Returns the mask of any invalid bits. If all bits are valid, returns 0.
  */
-uint32 CFlagsProperty::HasValidValue(void* pPropertyData)
+uint32 CFlagsProperty::HasValidValue(void* pPropertyData) const
 {
     if (!mAllFlags)
         return 0;
diff --git a/src/Core/Resource/Script/Property/CFlagsProperty.h b/src/Core/Resource/Script/Property/CFlagsProperty.h
index d88bedb9..1c701fef 100644
--- a/src/Core/Resource/Script/Property/CFlagsProperty.h
+++ b/src/Core/Resource/Script/Property/CFlagsProperty.h
@@ -68,7 +68,7 @@ public:
      * Checks whether there are any unrecognized bits toggled on in the property value.
      * Returns the mask of any invalid bits. If all bits are valid, returns 0.
      */
-    uint32 HasValidValue(void* pPropertyData);
+    uint32 HasValidValue(void* pPropertyData) const;
 };
 
 #endif // CFLAGSPROPERTY_H