diff --git a/core/base_rules.mk b/core/base_rules.mk
index d96502d..21b59a3 100644
--- a/core/base_rules.mk
+++ b/core/base_rules.mk
@@ -260,7 +260,7 @@
 my_path_components := $(subst /,$(space),$(LOCAL_PATH))
 my_path_prefix := MODULES-IN
 $(foreach c, $(my_path_components),\
-  $(eval my_path_prefix := $(my_path_prefix)/$(c))\
+  $(eval my_path_prefix := $(my_path_prefix)-$(c))\
   $(eval .PHONY : $(my_path_prefix))\
   $(eval $(my_path_prefix) : $(my_register_name)))
 
diff --git a/envsetup.sh b/envsetup.sh
index 1ff5f4a..c24e1f0 100644
--- a/envsetup.sh
+++ b/envsetup.sh
@@ -780,7 +780,10 @@
       return 1
     fi
     local MY_PWD=`PWD= /bin/pwd|sed 's:'$T'/::'`
-    $DRV make -C $T -f build/core/main.mk $@ MODULES-IN/$MY_PWD
+    local MODULES_IN_PATHS=MODULES-IN-$MY_PWD
+    # Convert "/" to "-".
+    MODULES_IN_PATHS=${MODULES_IN_PATHS//\//-}
+    $DRV make -C $T -f build/core/main.mk $@ $MODULES_IN_PATHS
   fi
 }
 
@@ -808,7 +811,7 @@
         if [ "$MY_PWD" != "" ]; then
           DIR=$MY_PWD/$DIR
         fi
-        MODULES_IN_PATHS="$MODULES_IN_PATHS MODULES-IN/$DIR"
+        MODULES_IN_PATHS="$MODULES_IN_PATHS MODULES-IN-$DIR"
       else
         case $DIR in
           showcommands | snod | dist | *=*) ARGS="$ARGS $DIR";;
@@ -816,6 +819,8 @@
         esac
       fi
     done
+    # Convert "/" to "-".
+    MODULES_IN_PATHS=${MODULES_IN_PATHS//\//-}
     $DRV make -C $T -f build/core/main.mk $DASH_ARGS $ARGS $MODULES_IN_PATHS
   else
     echo "Couldn't locate the top of the tree.  Try setting TOP."