diff --git a/lib/gssapi/Makefile.am b/lib/gssapi/Makefile.am
index 19e566af1..09330825f 100644
--- a/lib/gssapi/Makefile.am
+++ b/lib/gssapi/Makefile.am
@@ -54,6 +54,7 @@ krb5src = \
 	krb5/inquire_names_for_mech.c \
 	krb5/inquire_sec_context_by_oid.c \
 	krb5/process_context_token.c \
+	krb5/prf.c \
 	krb5/release_buffer.c \
 	krb5/release_cred.c \
 	krb5/release_name.c \