diff --git a/x11/xlockmore/Makefile b/x11/xlockmore/Makefile
index 4e2e31ed525d..d941519d4652 100644
--- a/x11/xlockmore/Makefile
+++ b/x11/xlockmore/Makefile
@@ -21,6 +21,7 @@ CONFIGURE_ARGS= --without-gl --without-motif --without-sx \
 		--without-nas --without-gtk --without-esound
 .if defined(MAKE_KERBEROS4)
 CONFIGURE_ARGS+= --enable-kerberos4
+KRB4LIB=	-lcom_err
 .endif
 .if defined(KRB5_HOME) && exists(${KRB5_HOME})
 CONFIGURE_ARGS+= --enable-kerberos5
@@ -39,7 +40,7 @@ USE_MESA=	yes
 .else
 CONFIGURE_ARGS+=	--without-mesa --without-opengl
 .endif
-CONFIGURE_ENV+=		XLOCKLIBS="${KRB5LIB} ${MESALIB}"
+CONFIGURE_ENV+=		XLOCKLIBS="${KRB5LIB} ${KRB4LIB} ${MESALIB}"
 
 .include <bsd.port.pre.mk>