diff --git a/runtime/doc/Makefile b/runtime/doc/Makefile
index 4ca0881..e10415f 100644
--- a/runtime/doc/Makefile
+++ b/runtime/doc/Makefile
@@ -323,9 +323,9 @@
 # Use Vim to generate the tags file.  Can only be used when Vim has been
 # compiled and installed.  Supports multiple languages.
 vimtags: $(DOCS)
-	@if which $(VIMEXE) >/dev/null; then \
-	  $(VIMEXE) --clean -eX -u doctags.vim >/dev/null; \
-	  echo "help tags updated"; \
+	@if command -v $(VIMEXE); then \
+	    $(VIMEXE) --clean -eX -u doctags.vim >/dev/null && \
+	      echo "help tags updated"; \
 	  else echo "vim executable $(VIMEXE) not found; help tags not updated"; fi
 
 # Use "doctags" to generate the tags file.  Only works for English!