diff --git a/src/libstrongswan/plugins/pkcs11/Makefile.am b/src/libstrongswan/plugins/pkcs11/Makefile.am
index 8babc34a5..0849fa914 100644
--- a/src/libstrongswan/plugins/pkcs11/Makefile.am
+++ b/src/libstrongswan/plugins/pkcs11/Makefile.am
@@ -1,5 +1,6 @@
 
-INCLUDES = -I$(top_srcdir)/src/libstrongswan
+INCLUDES = -I$(top_srcdir)/src/libstrongswan \
+	-I$(top_srcdir)/src/libcharon -I$(top_srcdir)/src/libhydra
 
 AM_CFLAGS = -rdynamic