diff --git a/services/core/java/com/android/server/SystemConfig.java b/services/core/java/com/android/server/SystemConfig.java
index 79620cf..1c1190f 100644
--- a/services/core/java/com/android/server/SystemConfig.java
+++ b/services/core/java/com/android/server/SystemConfig.java
@@ -1638,7 +1638,13 @@
                 String gidStr = parser.getAttributeValue(null, "gid");
                 if (gidStr != null) {
                     int gid = Process.getGidForName(gidStr);
-                    perm.gids = appendInt(perm.gids, gid);
+                    if (gid != -1) {
+                        perm.gids = appendInt(perm.gids, gid);
+                    } else {
+                        Slog.w(TAG, "<group> with unknown gid \""
+                                + gidStr + " for permission " + name + " in "
+                                + parser.getPositionDescription());
+                    }
                 } else {
                     Slog.w(TAG, "<group> without gid at "
                             + parser.getPositionDescription());