diff --git a/Makefile b/Makefile
--- a/Makefile
+++ b/Makefile
@@ -170,7 +170,7 @@ osx:
         # install zsh completions - this location appears to be
         # searched by default as of macOS Sierra.
 	install -d build/mercurial/usr/local/share/zsh/site-functions/
-	install -m 0644 contrib/zsh_completion build/mercurial/usr/local/share/zsh/site-functions/hg
+	install -m 0644 contrib/zsh_completion build/mercurial/usr/local/share/zsh/site-functions/_hg
         # install bash completions - there doesn't appear to be a
         # place that's searched by default for bash, so we'll follow
         # the lead of Apple's git install and just put it in a
diff --git a/tests/test-mac-packages.t b/tests/test-mac-packages.t
--- a/tests/test-mac-packages.t
+++ b/tests/test-mac-packages.t
@@ -29,8 +29,8 @@ Spot-check some randomly selected files:
   ./Library/Python/2.7/site-packages/mercurial/pure/bdiff.py	100644	0/0
   ./Library/Python/2.7/site-packages/mercurial/pure/bdiff.pyc	100644	0/0
   ./Library/Python/2.7/site-packages/mercurial/pure/bdiff.pyo	100644	0/0
-  $ grep zsh/site-functions/hg boms.txt | cut -d '	' -f 1,2,3
-  ./usr/local/share/zsh/site-functions/hg	100644	0/0
+  $ grep zsh/site-functions/_hg boms.txt | cut -d '	' -f 1,2,3
+  ./usr/local/share/zsh/site-functions/_hg	100644	0/0
   $ grep hg-completion.bash boms.txt | cut -d '	' -f 1,2,3
   ./usr/local/hg/contrib/hg-completion.bash	100644	0/0
   $ egrep 'man[15]' boms.txt | cut -d '	' -f 1,2,3