diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 63a106d392d..d34b55a8362 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,9 @@
+2010-04-13  Ian Lance Taylor  <iant@google.com>
+
+	* include/backward/hash_map: Don't #include "backward_warning.h"
+	if _GLIBCXX_PERMIT_BACKWARD_HASH is defined.
+	* include/backward/hash_set: Likewise.
+
 2010-04-12  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
 
 	* configure.host (os_include_dir): Removed solaris2.7 support.
diff --git a/libstdc++-v3/include/backward/hash_map b/libstdc++-v3/include/backward/hash_map
index 813ec472860..fe6e785c012 100644
--- a/libstdc++-v3/include/backward/hash_map
+++ b/libstdc++-v3/include/backward/hash_map
@@ -57,7 +57,10 @@
 #ifndef _BACKWARD_HASH_MAP
 #define _BACKWARD_HASH_MAP 1
 
+#ifndef _GLIBCXX_PERMIT_BACKWARD_HASH
 #include "backward_warning.h"
+#endif
+
 #include <bits/c++config.h>
 #include <backward/hashtable.h>
 #include <bits/concept_check.h>
diff --git a/libstdc++-v3/include/backward/hash_set b/libstdc++-v3/include/backward/hash_set
index 5a2ade78214..1e4f1a9792d 100644
--- a/libstdc++-v3/include/backward/hash_set
+++ b/libstdc++-v3/include/backward/hash_set
@@ -57,7 +57,10 @@
 #ifndef _BACKWARD_HASH_SET
 #define _BACKWARD_HASH_SET 1
 
+#ifndef _GLIBCXX_PERMIT_BACKWARD_HASH
 #include "backward_warning.h"
+#endif
+
 #include <bits/c++config.h>
 #include <backward/hashtable.h>
 #include <bits/concept_check.h>