diff --git a/srcpkgs/gsimplecal-gtk3/patches/invalid-cast.patch b/srcpkgs/gsimplecal-gtk3/patches/invalid-cast.patch
new file mode 100644
index 00000000000..6006f3a6f78
--- /dev/null
+++ b/srcpkgs/gsimplecal-gtk3/patches/invalid-cast.patch
@@ -0,0 +1,13 @@
+diff --git a/src/MainWindow.cpp b/src/MainWindow.cpp
+index 02eca42..323d5db 100644
+--- a/src/MainWindow.cpp
++++ b/src/MainWindow.cpp
+@@ -163,7 +163,7 @@ MainWindow::MainWindow()
+         closure = g_cclosure_new(G_CALLBACK(keys[key].func), (gpointer)this, NULL);
+         gtk_accel_group_connect(accelerators, keys[key].key,
+                                 (GdkModifierType)keys[key].modifier,
+-                                (GtkAccelFlags)NULL, closure);
++                                (GtkAccelFlags)0, closure);
+         g_closure_unref(closure);
+     }
+ 
diff --git a/srcpkgs/gsimplecal-gtk3/template b/srcpkgs/gsimplecal-gtk3/template
index a9a4b18141c..c5f4ebb2a37 100644
--- a/srcpkgs/gsimplecal-gtk3/template
+++ b/srcpkgs/gsimplecal-gtk3/template
@@ -1,6 +1,6 @@
 # Template file for 'gsimplecal-gtk3'
 pkgname=gsimplecal-gtk3
-version=2.4.1
+version=2.5
 revision=1
 build_style=gnu-configure
 hostmakedepends="automake pkg-config"
@@ -11,7 +11,7 @@ license="BSD-3-Clause"
 homepage="http://dmedvinsky.github.io/gsimplecal/"
 changelog="https://github.com/dmedvinsky/gsimplecal/raw/master/ChangeLog"
 distfiles="https://github.com/dmedvinsky/${pkgname%-*}/archive/v${version}.tar.gz"
-checksum=fd47df49ec26115bd6022d0e6a24648873c619e0406375d807fb18428d07d000
+checksum=f0be977de36fabc4da489698d2c06e64143572e53f166ab26e6055f6b36deae4
 
 pre_configure() {
 	./autogen.sh