diff --git a/rts/package.conf.in b/rts/package.conf.in
index 010305f83dec686e21dd8415745c147295df5fb0..4c8686f262036d39c1e703b6ebd5005e37ddbf95 100644
--- a/rts/package.conf.in
+++ b/rts/package.conf.in
@@ -57,9 +57,9 @@ extra-libraries:
 #endif
 
 #ifdef INSTALLING
-include-dirs:           INCLUDE_DIR PAPI_INCLUDE_DIR
+include-dirs:           INCLUDE_DIR PAPI_INCLUDE_DIR FFI_INCLUDE_DIR
 #else /* !INSTALLING */
-include-dirs:           TOP"/rts/dist/build" TOP"/includes" TOP"/includes/dist-derivedconstants/header"
+include-dirs:           TOP"/rts/dist/build" TOP"/includes" TOP"/includes/dist-derivedconstants/header" FFI_INCLUDE_DIR
 #endif
 
 includes:               Stg.h