f905ddb5-9113-c52a-d3ce-d0db83321d72:illumos $ git diff usr/src/man/man1/Makefile
diff --git a/usr/src/man/man1/Makefile b/usr/src/man/man1/Makefile
index a79713dfea..0c8095e4b9 100644
--- a/usr/src/man/man1/Makefile
+++ b/usr/src/man/man1/Makefile
@@ -750,8 +750,9 @@ zstdcat.1   := LINKSRC = zstd.1
 include                $(SRC)/man/Makefile.man

 ROOTMANFILES +=        $(ROOTMAN)/man$(MANSECT)/zstd.1
+ZSTD_SRC = $(SRC)/../../contrib/zstd/programs/

 install:       $(ROOTMANFILES) $(ROOTMANLINKS)

-$(ROOTMAN)/man$(MANSECT)/% : $(SRC)/../../contrib/zstd/programs/%
+$(ROOTMAN)/man$(MANSECT)/%: $(ZSTD_SRC)/% $(ROOTMAN)/man$(MANSECT)
        $(INS.file)