diff --git a/mozilla/configure b/mozilla/configure
index 3cbf218ad84..d9816809b05 100755
--- a/mozilla/configure
+++ b/mozilla/configure
@@ -981,7 +981,7 @@ _SUBDIR_CC="$CC"
 _SUBDIR_CXX="$CXX"
 _SUBDIR_CFLAGS="$CFLAGS"
 _SUBDIR_CPPFLAGS="$CPPFLAGS"
-_SUBDIR_CXXFLAGS="$CFLAGS"
+_SUBDIR_CXXFLAGS="$CXXFLAGS"
 _SUBDIR_LDFLAGS="$LDFLAGS"
 _SUBDIR_HOST_CC="$HOST_CC"
 _SUBDIR_HOST_CFLAGS="$HOST_CFLAGS"
diff --git a/mozilla/configure.in b/mozilla/configure.in
index c934eb9b270..6780722b9de 100644
--- a/mozilla/configure.in
+++ b/mozilla/configure.in
@@ -66,7 +66,7 @@ _SUBDIR_CC="$CC"
 _SUBDIR_CXX="$CXX"
 _SUBDIR_CFLAGS="$CFLAGS"
 _SUBDIR_CPPFLAGS="$CPPFLAGS"
-_SUBDIR_CXXFLAGS="$CFLAGS"
+_SUBDIR_CXXFLAGS="$CXXFLAGS"
 _SUBDIR_LDFLAGS="$LDFLAGS"
 _SUBDIR_HOST_CC="$HOST_CC"
 _SUBDIR_HOST_CFLAGS="$HOST_CFLAGS"