diff --git a/configure.in b/configure.in
index 65a530349be0b9286b48f0a3c7eda44b0f5b46d7..59a7ea736e12341527470173461b5a559d910307 100644
--- a/configure.in
+++ b/configure.in
@@ -241,10 +241,9 @@ esac
 
 AC_MSG_RESULT("setting default output device... $ao_default")
 
-LIBAO_FLAGS="$LIBAO_FLAGS -DAO_DEFAULT=$AO_DEFAULT_DEF"
+CFLAGS="$LIBAO_FLAGS -DAO_DEFAULT=$AO_DEFAULT_DEF"
 
 AC_SUBST(LIBAO_FILES)
-AC_SUBST(LIBAO_FLAGS)
 AC_SUBST(LIBAO_LIBS)
 
 AC_OUTPUT(Makefile src/Makefile doc/Makefile include/Makefile include/ao/Makefile include/ao/os_types.h include/ao/ao_libs.inc)
diff --git a/include/ao/ao.h b/include/ao/ao.h
index 7457dca57eefed825ed445dc0abcca3218f18022..b9835b6b77f56897bf879a1627cc3f4a99ff1dbc 100644
--- a/include/ao/ao.h
+++ b/include/ao/ao.h
@@ -28,9 +28,6 @@
 
 #include "os_types.h"
 
-// Type sizes
-#include "config.h"
-
 /* --- Structures --- */
 
 typedef struct ao_option_s {