diff --git a/configure.ac b/configure.ac
index 611d607..85aba74 100644
--- a/configure.ac
+++ b/configure.ac
@@ -46,14 +46,16 @@ AC_CONFIG_FILES([
 	libbcg729.pc
 ])
 
+VISIBILITY_CFLAGS=
 case "$target_os" in
 	*mingw*)
 		CFLAGS="$CFLAGS -D_WIN32_WINNT=0x0501"
 	;;
 	*)
-		CFLAGS="$CFLAGS -fvisibility=hidden"
+		VISIBILITY_CFLAGS="-fvisibility=hidden"
 	;;
 esac
+AC_SUBST(VISIBILITY_CFLAGS)
 
 
 AC_OUTPUT
diff --git a/src/Makefile.am b/src/Makefile.am
index af0dff0..c873934 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -27,3 +27,6 @@ libbcg729_la_SOURCES=	LP2LSPConversion.c \
 libbcg729_la_LDFLAGS= -no-undefined
 
 INCLUDES= -I$(top_srcdir)/include
+
+AM_CFLAGS=$(VISIBILITY_CFLAGS)
+