diff --git a/aegisub/src/Makefile.am b/aegisub/src/Makefile.am
index feec1f77e..ef43073bf 100644
--- a/aegisub/src/Makefile.am
+++ b/aegisub/src/Makefile.am
@@ -305,7 +305,7 @@ aegisub_2_2_SOURCES = \
 	video_context.cpp \
 	video_display.cpp \
 	video_frame.cpp \
-	video_out_gl.ccp \
+	video_out_gl.cpp \
 	video_provider_cache.cpp \
 	video_provider_dummy.cpp \
 	video_provider_manager.cpp \