diff --git a/glib-formaterror.patch b/glib-formaterror.patch
new file mode 100644
index 0000000..ecba4f7
--- /dev/null
+++ b/glib-formaterror.patch
@@ -0,0 +1,11 @@
+--- glib-2.57.1/configure.ac.orig	2018-08-02 05:42:37.295076670 +0200
++++ glib-2.57.1/configure.ac	2018-08-02 06:01:41.458209995 +0200
+@@ -3512,7 +3512,7 @@
+    -Werror=declaration-after-statement \
+    -Werror=missing-prototypes -Werror=implicit-function-declaration \
+    -Werror=pointer-arith -Werror=init-self -Werror=format-security \
+-   -Werror=format=2 -Werror=missing-include-dirs])
++   -Werror=missing-include-dirs])
+ ])
+ AC_SUBST(GLIB_WARN_CFLAGS)
+ 
diff --git a/mingw-glib2.spec b/mingw-glib2.spec
index 12b6f28..8bef615 100644
--- a/mingw-glib2.spec
+++ b/mingw-glib2.spec
@@ -50,6 +50,9 @@ Patch1:         0001-Use-CreateFile-on-Win32-to-make-sure-g_unlink-always.patch
 # https://bugzilla.gnome.org/show_bug.cgi?id=698118
 Patch5:         glib-prefer-constructors-over-DllMain.patch
 
+# Our GCC doesn't seem to properly understand %I64i format specifiers
+Patch6:         glib-formaterror.patch
+
 %description
 MinGW Windows Glib2 library.
 
@@ -95,6 +98,7 @@ Static version of the MinGW Windows GLib2 library.
 %setup -q -n glib-%{version}
 %patch1 -p1
 %patch5 -p1
+%patch6 -p0
 
 %build
 #GLib can't build static and shared libraries in one go, so we build GLib twice