diff --git a/mercurial/match.py b/mercurial/match.py
--- a/mercurial/match.py
+++ b/mercurial/match.py
@@ -1164,8 +1164,20 @@
 
     regex = ''
     if kindpats:
-        regex, mf = _buildregexmatch(kindpats, globsuffix)
-        matchfuncs.append(mf)
+        if all(k == 'rootfilesin' for k, p, s in kindpats):
+            dirs = {p for k, p, s in kindpats}
+            def mf(f):
+                i = f.rfind('/')
+                if i >= 0:
+                    dir = f[:i]
+                else:
+                    dir = '.'
+                return dir in dirs
+            regex = b'rootfilesin: %s' % sorted(dirs)
+            matchfuncs.append(mf)
+        else:
+            regex, mf = _buildregexmatch(kindpats, globsuffix)
+            matchfuncs.append(mf)
 
     if len(matchfuncs) == 1:
         return regex, matchfuncs[0]
diff --git a/tests/test-walk.t b/tests/test-walk.t
--- a/tests/test-walk.t
+++ b/tests/test-walk.t
@@ -143,25 +143,25 @@
 
   $ hg debugwalk -v 'rootfilesin:'
   * matcher:
-  <patternmatcher patterns='(?:[^/]+$)'>
+  <patternmatcher patterns="rootfilesin: ['.']">
   f  fennel      ../fennel
   f  fenugreek   ../fenugreek
   f  fiddlehead  ../fiddlehead
   $ hg debugwalk -v -I 'rootfilesin:'
   * matcher:
-  <includematcher includes='(?:[^/]+$)'>
+  <includematcher includes="rootfilesin: ['.']">
   f  fennel      ../fennel
   f  fenugreek   ../fenugreek
   f  fiddlehead  ../fiddlehead
   $ hg debugwalk -v 'rootfilesin:.'
   * matcher:
-  <patternmatcher patterns='(?:[^/]+$)'>
+  <patternmatcher patterns="rootfilesin: ['.']">
   f  fennel      ../fennel
   f  fenugreek   ../fenugreek
   f  fiddlehead  ../fiddlehead
   $ hg debugwalk -v -I 'rootfilesin:.'
   * matcher:
-  <includematcher includes='(?:[^/]+$)'>
+  <includematcher includes="rootfilesin: ['.']">
   f  fennel      ../fennel
   f  fenugreek   ../fenugreek
   f  fiddlehead  ../fiddlehead
@@ -169,7 +169,7 @@
   * matcher:
   <differencematcher
     m1=<alwaysmatcher>,
-    m2=<includematcher includes='(?:[^/]+$)'>>
+    m2=<includematcher includes="rootfilesin: ['.']">>
   f  beans/black                     ../beans/black
   f  beans/borlotti                  ../beans/borlotti
   f  beans/kidney                    ../beans/kidney
@@ -182,19 +182,19 @@
   f  mammals/skunk                   skunk
   $ hg debugwalk -v 'rootfilesin:fennel'
   * matcher:
-  <patternmatcher patterns='(?:fennel/[^/]+$)'>
+  <patternmatcher patterns="rootfilesin: ['fennel']">
   $ hg debugwalk -v -I 'rootfilesin:fennel'
   * matcher:
-  <includematcher includes='(?:fennel/[^/]+$)'>
+  <includematcher includes="rootfilesin: ['fennel']">
   $ hg debugwalk -v 'rootfilesin:skunk'
   * matcher:
-  <patternmatcher patterns='(?:skunk/[^/]+$)'>
+  <patternmatcher patterns="rootfilesin: ['skunk']">
   $ hg debugwalk -v -I 'rootfilesin:skunk'
   * matcher:
-  <includematcher includes='(?:skunk/[^/]+$)'>
+  <includematcher includes="rootfilesin: ['skunk']">
   $ hg debugwalk -v 'rootfilesin:beans'
   * matcher:
-  <patternmatcher patterns='(?:beans/[^/]+$)'>
+  <patternmatcher patterns="rootfilesin: ['beans']">
   f  beans/black     ../beans/black
   f  beans/borlotti  ../beans/borlotti
   f  beans/kidney    ../beans/kidney
@@ -203,7 +203,7 @@
   f  beans/turtle    ../beans/turtle
   $ hg debugwalk -v -I 'rootfilesin:beans'
   * matcher:
-  <includematcher includes='(?:beans/[^/]+$)'>
+  <includematcher includes="rootfilesin: ['beans']">
   f  beans/black     ../beans/black
   f  beans/borlotti  ../beans/borlotti
   f  beans/kidney    ../beans/kidney
@@ -212,25 +212,25 @@
   f  beans/turtle    ../beans/turtle
   $ hg debugwalk -v 'rootfilesin:mammals'
   * matcher:
-  <patternmatcher patterns='(?:mammals/[^/]+$)'>
+  <patternmatcher patterns="rootfilesin: ['mammals']">
   f  mammals/skunk  skunk
   $ hg debugwalk -v -I 'rootfilesin:mammals'
   * matcher:
-  <includematcher includes='(?:mammals/[^/]+$)'>
+  <includematcher includes="rootfilesin: ['mammals']">
   f  mammals/skunk  skunk
   $ hg debugwalk -v 'rootfilesin:mammals/'
   * matcher:
-  <patternmatcher patterns='(?:mammals/[^/]+$)'>
+  <patternmatcher patterns="rootfilesin: ['mammals']">
   f  mammals/skunk  skunk
   $ hg debugwalk -v -I 'rootfilesin:mammals/'
   * matcher:
-  <includematcher includes='(?:mammals/[^/]+$)'>
+  <includematcher includes="rootfilesin: ['mammals']">
   f  mammals/skunk  skunk
   $ hg debugwalk -v -X 'rootfilesin:mammals'
   * matcher:
   <differencematcher
     m1=<alwaysmatcher>,
-    m2=<includematcher includes='(?:mammals/[^/]+$)'>>
+    m2=<includematcher includes="rootfilesin: ['mammals']">>
   f  beans/black                     ../beans/black
   f  beans/borlotti                  ../beans/borlotti
   f  beans/kidney                    ../beans/kidney