diff --git a/funcs/func_groupcount.c b/funcs/func_groupcount.c
index 81c4c97c97df9b3058b8db270d33c44ac8fe31c2..4ee88a882f54f56af9cc4e46486b6a56acb01485 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 {