diff --git a/ChangeLog.csl b/ChangeLog.csl
index 24f721aaf..83d7bbb6d 100644
--- a/ChangeLog.csl
+++ b/ChangeLog.csl
@@ -1,3 +1,9 @@
+2006-08-22  Paul Brook  <paul@codesourcery.com>
+
+	newlib/
+	* libc/sys/arm/syscalls.c (initialise_monitor_handles): Fix
+	multithreaded locking.
+
 2006-07-24  Nathan Sidwell  <nathan@codesourcery.com>
 
 	Bug 844
diff --git a/newlib/libc/sys/arm/syscalls.c b/newlib/libc/sys/arm/syscalls.c
index ebbd087e4..33610c2e1 100644
--- a/newlib/libc/sys/arm/syscalls.c
+++ b/newlib/libc/sys/arm/syscalls.c
@@ -112,10 +112,11 @@ initialise_monitor_handles (void)
 
 #ifndef __SINGLE_THREAD__
   __lock_acquire_recursive (__arm_monitor_handles_lock);
-#endif
-  initialized = 1;
-#ifndef __SINGLE_THREAD__
-  __lock_release_recursive (__arm_monitor_handles_lock);
+  if (initialized)
+    {
+      __lock_release_recursive (__arm_monitor_handles_lock);
+      return;
+    }
 #endif
 
 #ifdef ARM_RDI_MONITOR
@@ -156,6 +157,11 @@ initialise_monitor_handles (void)
   openfiles[0].pos = 0;
   openfiles[1].handle = monitor_stdout;
   openfiles[1].pos = 0;
+
+  initialized = 1;
+#ifndef __SINGLE_THREAD__
+  __lock_release_recursive (__arm_monitor_handles_lock);
+#endif
 }
 
 static int