diff --git a/daemon/gdm-server.c b/daemon/gdm-server.c
index e9ed14ca11d51fae53943db6df4abf1d57948135..cca44c58b5287fc8af0c4874b972fd49c721d004 100644
--- a/daemon/gdm-server.c
+++ b/daemon/gdm-server.c
@@ -275,7 +275,8 @@ gdm_server_resolve_command_line (GdmServer  *server,
 
         gdm_server_init_command (server);
 
-        g_shell_parse_argv (server->command, &argc, &argv, NULL);
+        if (!g_shell_parse_argv (server->command, &argc, &argv, NULL))
+                return FALSE;
 
         for (len = 0; argv != NULL && argv[len] != NULL; len++) {
                 char *arg = argv[len];
@@ -670,10 +671,13 @@ gdm_server_spawn (GdmServer    *server,
         /* Figure out the server command */
         argv = NULL;
         argc = 0;
-        gdm_server_resolve_command_line (server,
-                                         vtarg,
-                                         &argc,
-                                         &argv);
+
+        if (!gdm_server_resolve_command_line (server,
+                                              vtarg,
+                                              &argc,
+                                              &argv)) {
+                return FALSE;
+        }
 
         if (server->session_args) {
                 server_add_xserver_args (server, &argc, &argv);
diff --git a/libgdm/gdm-sessions.c b/libgdm/gdm-sessions.c
index b0258d84d4b9a7eeaaaebba621e6db096dbbabc1..0aedcf90604cd3af02c03ff7929fe808ce15ab5a 100644
--- a/libgdm/gdm-sessions.c
+++ b/libgdm/gdm-sessions.c
@@ -79,6 +79,9 @@ get_systemd_session (void)
         else
                 ret = sd_pid_get_session (pid, &session_id);
 
+        if (ret < 0)
+                return NULL;
+
         return g_steal_pointer (&session_id);
 }