diff --git a/docs/Makefile.am b/docs/Makefile.am
index 1b2d9ff40..a3f9ec44f 100644
--- a/docs/Makefile.am
+++ b/docs/Makefile.am
@@ -24,7 +24,7 @@ EXTRA_DIST = MANUAL BUGS CONTRIBUTE FAQ FEATURES INTERNALS SSLCERTS	\
 	     VERSIONS KNOWN_BUGS BINDINGS $(man_MANS) $(HTMLPAGES) \
 	     HISTORY INSTALL libcurl-the-guide $(PDFPAGES)
 
-MAN2HTML= gnroff -man $< | man2html >$@
+MAN2HTML= $(NROFF) -man $< | man2html >$@
 
 SUFFIXES = .1 .3 .html .pdf
 
diff --git a/docs/libcurl/Makefile.am b/docs/libcurl/Makefile.am
index c90a99003..41e4838b6 100644
--- a/docs/libcurl/Makefile.am
+++ b/docs/libcurl/Makefile.am
@@ -122,7 +122,7 @@ CLEANFILES = $(HTMLPAGES) $(PDFPAGES)
 
 EXTRA_DIST = $(man_MANS) $(HTMLPAGES) index.html $(PDFPAGES)
 
-MAN2HTML= gnroff -man $< | man2html >$@
+MAN2HTML= $(NROFF) -man $< | man2html >$@
 
 SUFFIXES = .3 .html