diff --git a/rdoff/rdf2bin.1 b/rdoff/rdf2bin.1
index 88120ba9..d274d580 100644
--- a/rdoff/rdf2bin.1
+++ b/rdoff/rdf2bin.1
@@ -5,7 +5,7 @@ rdf2bin, rdf2com \- convert an RDOFF object file to flat binary
 .B rdf2bin
 .RI "[\-o " relocation-origin ]
 .RI "[\-p " segment-alignment ]
-.RI "[\-f" format ]
+.RI "[\-f " format ]
 .I input-file
 .I output-file
 .br