Index: sys/conf/kern.post.mk
===================================================================
--- sys/conf/kern.post.mk
+++ sys/conf/kern.post.mk
@@ -416,11 +416,11 @@
 	${OBJCOPY} \
 	    --rename-section .data=mfs,contents,alloc,load,readonly,data \
 	    --redefine-sym \
-		_binary_${MFS_IMAGE:C,[^-[:alnum:]],_,g}_size=__mfs_root_size \
+		_binary_${MFS_IMAGE:C,[^-/[:alnum:]],_,g}_size=__mfs_root_size \
 	    --redefine-sym \
-		_binary_${MFS_IMAGE:C,[^-[:alnum:]],_,g}_start=mfs_root \
+		_binary_${MFS_IMAGE:C,[^-/[:alnum:]],_,g}_start=mfs_root \
 	    --redefine-sym \
-		_binary_${MFS_IMAGE:C,[^-[:alnum:]],_,g}_end=mfs_root_end \
+		_binary_${MFS_IMAGE:C,[^-/[:alnum:]],_,g}_end=mfs_root_end \
 	    ${.TARGET}
 .endif
 .endif