diff --git a/harbour/include/hbapi.h b/harbour/include/hbapi.h
index 88bae5abeb..9c53fb9c92 100644
--- a/harbour/include/hbapi.h
+++ b/harbour/include/hbapi.h
@@ -98,7 +98,7 @@ extern "C" {
 #define HB_IS_LOGICAL( p ) HB_IS_OF_TYPE( p, HB_IT_LOGICAL )
 #define HB_IS_LONG( p )    HB_IS_OF_TYPE( p, HB_IT_LONG )
 #define HB_IS_NUMERIC( p ) ( ( p )->type & HB_IT_NUMERIC )
-#define HB_IS_OBJECT( p )  HB_IS_OF_TYPE( p, HB_IT_OBJECT )
+#define HB_IS_OBJECT( p )  ( HB_IS_OF_TYPE( p, HB_IT_OBJECT ) && ( p )->item.asArray.value->uiClass != 0 )
 #define HB_IS_STRING( p )  ( ( ( p )->type & ~( HB_IT_BYREF | HB_IT_MEMOFLAG ) ) == HB_IT_STRING )
 #define HB_IS_MEMO( p )    HB_IS_OF_TYPE( p, HB_IT_MEMO )
 #define HB_IS_SYMBOL( p )  HB_IS_OF_TYPE( p, HB_IT_SYMBOL )
@@ -581,4 +581,3 @@ extern void   hb_verBuildInfo( void ); /* display harbour, compiler, and platfor
 #endif
 
 #endif /* HB_APIEXT_H_ */
-