diff --git a/src/plugins/exec/exec.c b/src/plugins/exec/exec.c
index b6312f472..44544628d 100644
--- a/src/plugins/exec/exec.c
+++ b/src/plugins/exec/exec.c
@@ -89,7 +89,7 @@ exec_search_by_id (const char *id)
     error = NULL;
     number = strtol (id, &error, 10);
     if (!error || error[0])
-        number = -1;
+        return NULL;
 
     for (ptr_exec_cmd = exec_cmds; ptr_exec_cmd;
          ptr_exec_cmd = ptr_exec_cmd->next_cmd)