diff --git a/mercurial/sparse.py b/mercurial/sparse.py
--- a/mercurial/sparse.py
+++ b/mercurial/sparse.py
@@ -718,7 +718,7 @@
 
     The new config is written out and a working directory refresh is performed.
     """
-    with repo.wlock(), repo.dirstate.parentchange():
+    with repo.wlock(), repo.lock(), repo.dirstate.parentchange():
         raw = repo.vfs.tryread(b'sparse')
         oldinclude, oldexclude, oldprofiles = parseconfig(
             repo.ui, raw, b'sparse'
diff --git a/tests/test-sparse-with-safe-share.t b/tests/test-sparse-with-safe-share.t
--- a/tests/test-sparse-with-safe-share.t
+++ b/tests/test-sparse-with-safe-share.t
@@ -16,10 +16,8 @@
   $ echo x > hide
   $ hg ci -Aqm 'initial'
 
-Verify basic --include
+Regression test: checks that this command correctly locks the store
+before updating the store [requirements] config.
 
   $ hg up -q 0
   $ hg debugsparse --include 'hide'
-  devel-warn: write with no lock: "requires" at: *mercurial/scmutil.py:1558 (writerequires) (glob)
-
-TODO: bug in sparse when used together with safe-share^