diff --git a/external/fontconfig/UnpackedTarball_fontconfig.mk b/external/fontconfig/UnpackedTarball_fontconfig.mk
index 19b093e7ca39..b439ec4bf2c3 100644
--- a/external/fontconfig/UnpackedTarball_fontconfig.mk
+++ b/external/fontconfig/UnpackedTarball_fontconfig.mk
@@ -21,6 +21,7 @@ $(eval $(call gb_UnpackedTarball_add_patches,fontconfig,\
 ifneq ($(OS),MACOSX)
 $(eval $(call gb_UnpackedTarball_add_patches,fontconfig,\
 	external/fontconfig/libfontconfig-bundled-soname.patch.0 \
+	external/fontconfig/locale_t_macOS.patch.1 \
 ))
 endif
 
diff --git a/external/fontconfig/locale_t_macOS.patch.1 b/external/fontconfig/locale_t_macOS.patch.1
new file mode 100644
index 000000000000..2d813bec295b
--- /dev/null
+++ b/external/fontconfig/locale_t_macOS.patch.1
@@ -0,0 +1,14 @@
+diff -ur fontconfig.org/src/fcint.h fontconfig/src/fcint.h
+--- fontconfig.org/src/fcint.h	2026-07-19 16:48:28.916116391 +0200
++++ fontconfig/src/fcint.h	2026-07-19 16:50:01.131629047 +0200
+@@ -29,6 +29,10 @@
+ #  include <config.h>
+ #endif
+ 
++#ifdef HAVE_XLOCALE_H
++#include <xlocale.h>
++#endif
++
+ #include "fcstdint.h"
+ 
+ #include <assert.h>