diff --git a/usr.bin/units/units.1 b/usr.bin/units/units.1
index 4b73da4eb09..a7173a5c586 100644
--- a/usr.bin/units/units.1
+++ b/usr.bin/units/units.1
@@ -149,7 +149,7 @@ The
 program will not detect infinite loops that could be caused
 by careless unit definitions.
 Comments in the unit definition file
-begin with a '/' character at the beginning of a line.
+begin with a '#' or '/' character at the beginning of a line.
 .Pp
 Prefixes are defined in the same was as standard units, but with
 a trailing dash at the end of the prefix name.
diff --git a/usr.bin/units/units.c b/usr.bin/units/units.c
index f8e4f11bb24..94a976f98ce 100644
--- a/usr.bin/units/units.c
+++ b/usr.bin/units/units.c
@@ -166,7 +166,7 @@ readunits(const char *userfile)
 			break;
 		linenum++;
 		lineptr = line;
-		if (*lineptr == '/')
+		if (*lineptr == '/' || *lineptr == '#')
 			continue;
 		lineptr += strspn(lineptr, " \n\t");
 		len = strcspn(lineptr, " \n\t");