diff --git a/FFmpegSource2/Makefile.am b/FFmpegSource2/Makefile.am
index 2d64770be..89eafbde7 100644
--- a/FFmpegSource2/Makefile.am
+++ b/FFmpegSource2/Makefile.am
@@ -1,6 +1,6 @@
 noinst_LIBRARIES = libffmpegsource2_aegisub.a
 
-AM_CPPFLAGS = -include ../aegisub/posix/defines.h -I../aegisub @WX_CPPFLAGS@
+AM_CPPFLAGS = -I../aegisub @WX_CPPFLAGS@
 
 libffmpegsource2_aegisub_a_SOURCES = \
 	ffaudiosource.cpp \
diff --git a/aegisub/Makefile.am b/aegisub/Makefile.am
index 3ba5b143c..e9339330b 100644
--- a/aegisub/Makefile.am
+++ b/aegisub/Makefile.am
@@ -10,7 +10,7 @@ endif
 
 SUBDIRS = bitmaps posix $(libosxutil_subdir)
 
-AM_CXXFLAGS = -DAEGISUB -Iposix -include posix/defines.h -Iinclude @WX_CPPFLAGS@ @OPENMP_CXXFLAGS@
+AM_CXXFLAGS = -DAEGISUB -Iposix -Iinclude @WX_CPPFLAGS@ @OPENMP_CXXFLAGS@
 
 bin_PROGRAMS = aegisub
 aegisub_LDADD = posix/libposix.a $(libosxutil_lib)