diff --git a/build/autoconf/libstdcxx.py b/build/autoconf/libstdcxx.py
index 35008918e6d..15fe60fe32e 100755
--- a/build/autoconf/libstdcxx.py
+++ b/build/autoconf/libstdcxx.py
@@ -12,6 +12,7 @@
 import os
 import subprocess
 import re
+import sys
 
 re_for_ld = re.compile('.*\((.*)\).*')
 
@@ -67,7 +68,19 @@ def find_version(e):
     return encode_ver(last_version)
 
 if __name__ == '__main__':
-    cxx_env = os.environ['CXX']
-    print 'MOZ_LIBSTDCXX_TARGET_VERSION=%s' % find_version(cxx_env)
-    host_cxx_env = os.environ.get('HOST_CXX', cxx_env)
-    print 'MOZ_LIBSTDCXX_HOST_VERSION=%s' % find_version(host_cxx_env)
+    if os.uname()[0] == 'Darwin':
+        sdk_dir = os.environ['MACOS_SDK_DIR']
+        if 'MacOSX10.5.sdk' in sdk_dir:
+            target_ver = 0
+            host_ver = 0
+        else:
+            target_ver = encode_ver('3.4.9')
+            host_ver = encode_ver('3.4.9')
+    else:
+        cxx_env = os.environ['CXX']
+        target_ver = find_version(cxx_env)
+        host_cxx_env = os.environ.get('HOST_CXX', cxx_env)
+        host_ver = find_version(host_cxx_env)
+
+    print 'MOZ_LIBSTDCXX_TARGET_VERSION=%s' % target_ver
+    print 'MOZ_LIBSTDCXX_HOST_VERSION=%s' % host_ver
diff --git a/build/macosx/common b/build/macosx/common
index b52f56b29cf..b532039a234 100644
--- a/build/macosx/common
+++ b/build/macosx/common
@@ -1,2 +1,4 @@
 CC=/usr/bin/gcc-4.2
 CXX=/usr/bin/g++-4.2
+
+ac_add_options --enable-stdcxx-compat
diff --git a/build/stdc++compat.cpp b/build/stdc++compat.cpp
index 499304c37d4..a7f73af9556 100644
--- a/build/stdc++compat.cpp
+++ b/build/stdc++compat.cpp
@@ -57,6 +57,9 @@ namespace std {
     template ostream& ostream::_M_insert(double);
     template ostream& ostream::_M_insert(long);
     template ostream& ostream::_M_insert(unsigned long);
+#ifdef DEBUG
+    template ostream& ostream::_M_insert(const void*);
+#endif
     template ostream& __ostream_insert(ostream&, const char*, streamsize);
     template istream& istream::_M_extract(double&);
 #endif
diff --git a/configure.in b/configure.in
index 71005f0e299..21f3fb702e9 100644
--- a/configure.in
+++ b/configure.in
@@ -7466,7 +7466,7 @@ MOZ_ARG_ENABLE_BOOL(stdcxx-compat,
 AC_SUBST(STDCXX_COMPAT)
 
 if test -n "$STDCXX_COMPAT"; then
-   eval $(CXX="$CXX" $PYTHON $_topsrcdir/build/autoconf/libstdcxx.py)
+   eval $(CXX="$CXX" MACOS_SDK_DIR="$MACOS_SDK_DIR" $PYTHON $_topsrcdir/build/autoconf/libstdcxx.py)
    AC_SUBST(MOZ_LIBSTDCXX_TARGET_VERSION)
    AC_SUBST(MOZ_LIBSTDCXX_HOST_VERSION)
 fi