diff --git a/aegisub/libffms/Makefile.am b/aegisub/libffms/Makefile.am
index 7e4cd992f..e5119c7c2 100644
--- a/aegisub/libffms/Makefile.am
+++ b/aegisub/libffms/Makefile.am
@@ -25,4 +25,4 @@ libffmpegsource_aegisub_a_SOURCES = \
 	src/core/wave64writer.cpp
 
 libffmpegsource_aegisub_a_SOURCES += \
-	core/*.h
+	src/core/*.h