diff --git a/external/libnumbertext/UnpackedTarball_libnumbertext.mk b/external/libnumbertext/UnpackedTarball_libnumbertext.mk
index ac2a14133205..f5c1607562e3 100644
--- a/external/libnumbertext/UnpackedTarball_libnumbertext.mk
+++ b/external/libnumbertext/UnpackedTarball_libnumbertext.mk
@@ -13,4 +13,10 @@ $(eval $(call gb_UnpackedTarball_set_tarball,libnumbertext,$(LIBNUMBERTEXT_TARBA
 
 $(eval $(call gb_UnpackedTarball_update_autoconf_configs,libnumbertext))
 
+$(eval $(call gb_UnpackedTarball_set_patchlevel,libnumbertext,0))
+
+$(eval $(call gb_UnpackedTarball_add_patches,libnumbertext, \
+    external/libnumbertext/configure.patch \
+))
+
 # vim: set noet sw=4 ts=4:
diff --git a/external/libnumbertext/configure.patch b/external/libnumbertext/configure.patch
new file mode 100644
index 000000000000..f31ab31cdc57
--- /dev/null
+++ b/external/libnumbertext/configure.patch
@@ -0,0 +1,10 @@
+--- configure.ac
++++ configure.ac
+@@ -22,7 +22,6 @@
+ 
+ dnl Checks for typedefs, structures, and compiler characteristics.
+ AC_LANG([C++])
+-CXXFLAGS='-Wall -std=c++11'
+ 
+ AC_CHECK_HEADERS([codecvt regex])
+