diff --git a/project/extras.mk b/project/extras.mk
index 88b2766..d3d5211 100644
--- a/project/extras.mk
+++ b/project/extras.mk
@@ -1,6 +1,6 @@
 CFLAGS_SHARED_ATTR	+= -DPTYC_PRE_ALPHA -DPTYC_EXPORT
-CFLAGS_STATIC_ATTR	+= -DPTYC_PRE_ALPHA -DPTYC_STATIC
-CFLAGS_APP_ATTR		+= -DPTYC_APP
+CFLAGS_STATIC_ATTR	+= -DPTYC_PRE_ALPHA -DPTYC_STATIC -fvisibility=hidden
+CFLAGS_APP_ATTR		+= -DPTYC_APP -fvisibility=hidden
 
 CFLAGS_CONFIG 		+= -ffreestanding
 CFLAGS_CONFIG 		+= -D_MIDIPIX_FREESTANDING -D__NT$(HOST_BITS)