diff --git a/exec/coroparse.c b/exec/coroparse.c
index 374ed7dd..ac654a11 100644
--- a/exec/coroparse.c
+++ b/exec/coroparse.c
@@ -139,6 +139,12 @@ static int uid_determine (const char *req_user)
 	long int id;
 	char *ep;
 
+	if(*req_user == '\0') {
+	        sprintf (error_string_response,
+	               "The user can not be empty, please read the documentation.");
+	        return (-1);
+	}
+
 	id = strtol(req_user, &ep, 10);
 	if (*ep == '\0' && id >= 0 && id <= UINT_MAX) {
 		return (id);
@@ -193,6 +199,12 @@ static int gid_determine (const char *req_group)
 	long int id;
 	char *ep;
 
+	if(*req_group == '\0') {
+	        sprintf (error_string_response,
+	                "The group can not be empty, please read the documentation.");
+	        return (-1);
+	}
+
 	id = strtol(req_group, &ep, 10);
 	if (*ep == '\0' && id >= 0 && id <= UINT_MAX) {
 		return (id);
-- 
2.13.6