diff --git a/libxcrypt-4.4.6-crypt_kat_fix_Wformat.patch b/libxcrypt-4.4.6-crypt_kat_fix_Wformat.patch
new file mode 100644
index 0000000..30c6b2b
--- /dev/null
+++ b/libxcrypt-4.4.6-crypt_kat_fix_Wformat.patch
@@ -0,0 +1,22 @@
+From 313649452bacc8c076e1be466edb282a7482e5e0 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Bj=C3=B6rn=20Esser?= <besser82@fedoraproject.org>
+Date: Mon, 24 Jun 2019 15:43:00 +0200
+Subject: [PATCH] crypt-kat: Fix Wformat.
+
+---
+ test/crypt-kat.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/test/crypt-kat.c b/test/crypt-kat.c
+index 66a1fa2..985d27c 100644
+--- a/test/crypt-kat.c
++++ b/test/crypt-kat.c
+@@ -214,7 +214,7 @@ calc_hashes_crypt_r_rn (ARG_UNUSED (void *unused))
+   for (i = 0; i < ntests; i++)
+     {
+       strncpy(u.pass + 1, tests[i].input, CRYPT_MAX_PASSPHRASE_SIZE);
+-      printf("[%d]: %s %s\n", strlen(tests[i].input), tests[i].input, tests[i].salt);
++      printf("[%zu]: %s %s\n", strlen(tests[i].input), tests[i].input, tests[i].salt);
+       errno = 0;
+       hash = crypt_r (u.pass + 1, tests[i].salt, &data);
+       status |= report_result ("crypt_r", hash, errno, &tests[i],
diff --git a/libxcrypt.spec b/libxcrypt.spec
index f47b745..c72da11 100644
--- a/libxcrypt.spec
+++ b/libxcrypt.spec
@@ -152,6 +152,7 @@ URL:            https://github.com/besser82/%{name}
 Source0:        %{url}/archive/v%{version}/%{name}-%{version}.tar.gz
 
 # Patch 0000 - 2999: Backported patches from upstream.
+Patch0000:      %{url}/commit/313649452bacc8c076e1be466edb282a7482e5e0.patch#/%{name}-4.4.6-crypt_kat_fix_Wformat.patch
 
 # Patch 3000 - 5999: Backported patches from pull requests.
 
@@ -461,6 +462,7 @@ done
 %changelog
 * Mon Jun 24 2019 Björn Esser <besser82@fedoraproject.org> - 4.4.6-2
 - Build all hash methods for the compat package
+- Add a patch to fix Wformat in crypt-kat.c
 
 * Sun May 05 2019 Björn Esser <besser82@fedoraproject.org> - 4.4.6-1
 - New upstream release