diff --git a/libjava/ChangeLog b/libjava/ChangeLog
index 6c5c4d10e7bb..742e94b036cb 100644
--- a/libjava/ChangeLog
+++ b/libjava/ChangeLog
@@ -1,3 +1,8 @@
+2003-10-23  Rainer Orth  <ro@TechFak.Uni-Bielefeld.DE>
+
+	* java/lang/natObject.cc (_Jv_ObjectCheckMonitor): Use
+	_Jv_MutexCheckMonitor instead of accessing mutex.owner directly.
+
 2003-10-22  Tom Tromey  <tromey@redhat.com>
 
 	PR libgcj/12416:
diff --git a/libjava/java/lang/natObject.cc b/libjava/java/lang/natObject.cc
index a9f80d867f80..8618bf2c7a3a 100644
--- a/libjava/java/lang/natObject.cc
+++ b/libjava/java/lang/natObject.cc
@@ -1127,7 +1127,7 @@ retry:
   else
     {
       heavy_lock* hl = find_heavy(addr, he);
-      not_mine = hl ? (hl->si.mutex.owner != self) : true;
+      not_mine = hl ? _Jv_MutexCheckMonitor(&hl->si.mutex) : true;
     }
 
   release_set(&(he -> address), address);	// unlock hash entry