diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 43ecc7bb90c..9c74e5958cd 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,8 @@
+2013-05-24  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
+
+	* config/os/solaris/solaris2.9/os_defines.h [!CLOCK_MONOTONIC]
+	(CLOCK_MONOTONIC): Define.
+
 2013-05-24  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	* include/ext/type_traits.h (__is_null_pointer): Add std::nullptr_t
diff --git a/libstdc++-v3/config/os/solaris/solaris2.9/os_defines.h b/libstdc++-v3/config/os/solaris/solaris2.9/os_defines.h
index 70586d1c1bd..ed30abbe244 100644
--- a/libstdc++-v3/config/os/solaris/solaris2.9/os_defines.h
+++ b/libstdc++-v3/config/os/solaris/solaris2.9/os_defines.h
@@ -35,5 +35,10 @@
 #define __CORRECT_ISO_CPP_WCHAR_H_PROTO
 #endif
 
+/* Solaris 9 uses the non-standard CLOCK_HIGHRES instead.  */
+#ifndef CLOCK_MONOTONIC
+#define CLOCK_MONOTONIC CLOCK_HIGHRES
+#endif
+
 #endif