diff --git a/funcs/func_groupcount.c b/funcs/func_groupcount.c
index 81c4c97c97..4ee88a882f 100644
--- a/funcs/func_groupcount.c
+++ b/funcs/func_groupcount.c
@@ -196,6 +196,10 @@ static int group_function_write(struct ast_channel *chan, const char *cmd,
 {
 	char grpcat[256];
 
+	if (!value) {
+		return -1;
+	}
+
 	if (!ast_strlen_zero(data)) {
 		snprintf(grpcat, sizeof(grpcat), "%s@%s", value, data);
 	} else {