diff --git a/src/vim9script.c b/src/vim9script.c
index 3780356..fa455ab 100644
--- a/src/vim9script.c
+++ b/src/vim9script.c
@@ -741,7 +741,9 @@
     {
 	svar_T    *sv = ((svar_T *)si->sn_var_vals.ga_data) + idx;
 
-	if (sv->sv_tv == dest)
+	// If "sv_name" is NULL the variable was hidden when leaving a block,
+	// don't check "sv_tv" then, it might be used for another variable now.
+	if (sv->sv_name != NULL && sv->sv_tv == dest)
 	    return sv;
     }
     iemsg("check_script_var_type(): not found");