diff --git a/dev-scheme/gauche-gl/files/gauche-gl-0.6-simple.viewer.diff b/dev-scheme/gauche-gl/files/gauche-gl-0.6-simple.viewer.patch
similarity index 100%
rename from dev-scheme/gauche-gl/files/gauche-gl-0.6-simple.viewer.diff
rename to dev-scheme/gauche-gl/files/gauche-gl-0.6-simple.viewer.patch
diff --git a/dev-scheme/gauche-gl/gauche-gl-0.6.ebuild b/dev-scheme/gauche-gl/gauche-gl-0.6.ebuild
index c8308043af563..ab4d26ce0bd00 100644
--- a/dev-scheme/gauche-gl/gauche-gl-0.6.ebuild
+++ b/dev-scheme/gauche-gl/gauche-gl-0.6.ebuild
@@ -1,4 +1,4 @@
-# Copyright 1999-2015 Gentoo Foundation
+# Copyright 1999-2017 Gentoo Foundation
 # Distributed under the terms of the GNU General Public License v2
 
 EAPI="5"
@@ -25,7 +25,7 @@ DEPEND="${RDEPEND}"
 S="${WORKDIR}/${MY_P}"
 
 src_prepare() {
-	epatch "${FILESDIR}"/${P}-simple.viewer.diff
+	epatch "${FILESDIR}"/${P}-simple.viewer.patch
 }
 
 src_configure() {