diff --git a/libstdc++/ChangeLog b/libstdc++/ChangeLog
index 6640d5d9137..b3d5b94dee9 100644
--- a/libstdc++/ChangeLog
+++ b/libstdc++/ChangeLog
@@ -1,3 +1,8 @@
+Sun Feb  1 13:38:07 1998  H.J. Lu  (hjl@gnu.org)
+
+	* config/linux.mt: Don't define _PTHREADS, but define
+	_IO_MTSAFE_IO.
+
 Wed Jan 28 10:27:11 1998  Manfred Hollstein  <manfred@s-direktnet.de>
 
         * tests/configure.in, testsuite/configure.in: Update with yesterday's
diff --git a/libstdc++/config/linux.mt b/libstdc++/config/linux.mt
index 6afe1e514d9..5848851be8a 100644
--- a/libstdc++/config/linux.mt
+++ b/libstdc++/config/linux.mt
@@ -1 +1,2 @@
-MT_CFLAGS = -D_PTHREADS
+# tell we want the mt-safe version
+MT_CFLAGS = -D_IO_MTSAFE_IO