diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index ee66ccb0cf1..8424ae59015 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,5 +1,8 @@
 2005-03-25  Mark Mitchell  <mark@codesourcery.com>
 
+	* testsuite/lib/libstdc++.exp (libstdc++_init): Define LOCALEDIR
+	when testing an installed compiler.
+	
 	* testsuite/lib/libstdc++.exp (v3-build_support): Pass -w when
 	compiling support objects.
 
diff --git a/libstdc++-v3/testsuite/lib/libstdc++.exp b/libstdc++-v3/testsuite/lib/libstdc++.exp
index 9c9ace29637..2f36c7faa55 100644
--- a/libstdc++-v3/testsuite/lib/libstdc++.exp
+++ b/libstdc++-v3/testsuite/lib/libstdc++.exp
@@ -183,6 +183,14 @@ proc libstdc++_init { testfile } {
             set cxx [transform "g++"]
             set cxxflags "-g -O2 -D_GLIBCXX_ASSERT -fmessage-length=0" 
             set includes "-I${srcdir}"
+	    # Guess at the location of the installed locale files.
+	    # (It would be nice if "gcc --print-file-name" could find
+	    # message files, but it cannot.)
+	    set absolute_cxx [which $cxx]
+	    if { $absolute_cxx != "" } {
+		set localedir "[file dirname $absolute_cxx]/../share/locale"
+	    }
+	    set cxxflags "$cxxflags -DLOCALEDIR=\"$localedir\""
         }
     }