diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index a253d443565c..6240492f8bb1 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,8 @@
+2001-05-07  Mark Mitchell  <mark@codesourcery.com>
+
+	* config/os/solaris/solaris2.7/bits/os_defines.h
+	(_LARGEFILE_SOURCE): Define it.
+
 2001-05-03  Alexandre Oliva  <aoliva@redhat.com>
 
 	* configure.in (LIBSUPCXX_PICFLAGS): Set it to -prefer-pic or
diff --git a/libstdc++-v3/config/os/solaris/solaris2.7/bits/os_defines.h b/libstdc++-v3/config/os/solaris/solaris2.7/bits/os_defines.h
index 91e0261bd95d..ec63697886bb 100644
--- a/libstdc++-v3/config/os/solaris/solaris2.7/bits/os_defines.h
+++ b/libstdc++-v3/config/os/solaris/solaris2.7/bits/os_defines.h
@@ -33,6 +33,7 @@
 
 // Need these to get sane definitions, esp. of 64-bit types and typedefs.
 #define _XOPEN_SOURCE        500
+#define _LARGEFILE_SOURCE    1
 #define _LARGEFILE64_SOURCE  1
 #define __EXTENSIONS__