Index: head/emulators/virtualbox-ose-kmod/Makefile
===================================================================
--- head/emulators/virtualbox-ose-kmod/Makefile
+++ head/emulators/virtualbox-ose-kmod/Makefile
@@ -74,6 +74,13 @@
 
 .include <bsd.port.pre.mk>
 
+.if ${OSREL:R} >= 11
+SYMBOLSUFFIX=	debug
+.else
+SYMBOLSUFFIX=	symbols
+.endif
+PLIST_SUB+=	SYMBOLSUFFIX=${SYMBOLSUFFIX}
+
 post-patch:
 	@${ECHO} 'VBOX_WITH_VBOXDRV = 1' > ${WRKSRC}/LocalConfig.kmk
 	@${ECHO} 'VBOX_WITH_NETFLT = 1' >> ${WRKSRC}/LocalConfig.kmk
@@ -97,7 +104,7 @@
 .for i in ${VBOX_KMODS}
 	${INSTALL_KLD} ${VBOX_BIN}/${i}/${i}.ko ${STAGEDIR}${KMODDIR}
 .if ${PORT_OPTIONS:MDEBUG}
-	${INSTALL_KLD} ${VBOX_BIN}/${i}/${i}.ko.symbols ${STAGEDIR}${KMODDIR}
+	${INSTALL_KLD} ${VBOX_BIN}/${i}/${i}.ko.${SYMBOLSUFFIX} ${STAGEDIR}${KMODDIR}
 .endif
 .endfor
 
Index: head/emulators/virtualbox-ose-kmod/pkg-plist
===================================================================
--- head/emulators/virtualbox-ose-kmod/pkg-plist
+++ head/emulators/virtualbox-ose-kmod/pkg-plist
@@ -1,6 +1,6 @@
 /%%KMODDIR%%/vboxdrv.ko
-%%DEBUG%%/%%KMODDIR%%/vboxdrv.ko.symbols
+%%DEBUG%%/%%KMODDIR%%/vboxdrv.ko.%%SYMBOLSUFFIX%%
 /%%KMODDIR%%/vboxnetadp.ko
-%%DEBUG%%/%%KMODDIR%%/vboxnetadp.ko.symbols
+%%DEBUG%%/%%KMODDIR%%/vboxnetadp.ko.%%SYMBOLSUFFIX%%
 /%%KMODDIR%%/vboxnetflt.ko
-%%DEBUG%%/%%KMODDIR%%/vboxnetflt.ko.symbols
+%%DEBUG%%/%%KMODDIR%%/vboxnetflt.ko.%%SYMBOLSUFFIX%%