diff --git a/project/extras.mk b/project/extras.mk
index f9ddb03..3bf3bac 100644
--- a/project/extras.mk
+++ b/project/extras.mk
@@ -1,5 +1,5 @@
-CFLAGS_SHARED_ATTR 	+= -DPE_EXPORT
-CFLAGS_STATIC_ATTR 	+= -DPE_STATIC
+CFLAGS_SHARED_ATTR 	+= -DPE_EXPORT -fvisibility=hidden
+CFLAGS_STATIC_ATTR 	+= -DPE_STATIC -fvisibility=hidden
 
 CFLAGS_CONFIG 		+= -D_MIDIPIX_FREESTANDING -D__NT$(HOST_BITS)
 CFLAGS_CONFIG 		+= -UWIN32 -U_WIN32 -U__WIN32 -U__WIN32__