diff --git a/aegisub/libffms/Makefile.am b/aegisub/libffms/Makefile.am
index 851d4cea6..2204f3dae 100644
--- a/aegisub/libffms/Makefile.am
+++ b/aegisub/libffms/Makefile.am
@@ -22,4 +22,5 @@ libffmpegsource_aegisub_a_SOURCES = \
 	src/core/wave64writer.cpp
 
 libffmpegsource_aegisub_a_SOURCES += \
-	src/core/*.h
+	src/core/*.h \
+	include/*.h