diff --git a/src/vim9.h b/src/vim9.h
index 310b59e..b3d5bc2 100644
--- a/src/vim9.h
+++ b/src/vim9.h
@@ -207,7 +207,7 @@
 
 // arguments to ISN_CHECKTYPE
 typedef struct {
-    vartype_T	ct_type;
+    type_T	*ct_type;
     int		ct_off;	    // offset in stack, -1 is bottom
 } checktype_T;