diff --git a/pkgs/tools/graphics/graphviz/default.nix b/pkgs/tools/graphics/graphviz/default.nix
index 96ae324b01f0..a5d2d20968a8 100644
--- a/pkgs/tools/graphics/graphviz/default.nix
+++ b/pkgs/tools/graphics/graphviz/default.nix
@@ -32,8 +32,10 @@ stdenv.mkDerivation rec {
     sed -e 's@am__append_5 *=.*@am_append_5 =@' -i lib/gvc/Makefile
   '';
 
+  # "command -v" is POSIX, "which" is not
   postInstall = ''
     sed -i 's|`which lefty`|"'$out'/bin/lefty"|' $out/bin/dotty
+    sed -i 's|which|command -v|' $out/bin/vimdot
   '';
 
   meta = {