diff --git a/util/openssl-format-source b/util/openssl-format-source
index 4ea2f1bbd9f883b733d1cd0d894257ab75f4e08c..725883601f5c4bce1b799797b315a16bc4071660 100755
--- a/util/openssl-format-source
+++ b/util/openssl-format-source
@@ -21,6 +21,9 @@ HERE="`dirname $0`"
 
 set -e
 
+INDENT=indent
+uname -s | grep BSD > /dev/null && type gindent > /dev/null 2>&1 && INDENT=gindent
+
 if [ $# -eq 0 ]; then
   echo "usage: $0 [-v] [-n] [-c] [sourcefile|sourcedir] ..." >&2
   exit 1
@@ -120,11 +123,11 @@ do
 	      -e '/ASN1_(ITEM_ref|ITEM_ptr|ITEM_rptr|PCTX)/ || s/^((ASN1|ADB)_[^\*]*[){=,]+[ \t]*)$/\/**INDENT-OFF**\/\n$1/;' \
 	      -e 's/^(} (ASN1|ADB)_[^\*]*[\){=,;]+)$/$1\n\/**INDENT-ON**\//;' \
 	      | \
-	      $DEBUG indent $INDENT_ARGS | \
+	      $DEBUG $INDENT $INDENT_ARGS | \
 	      perl -np \
 		-e 's/^([ \t]*)\/\*-(.*)\*\/[ \t]*$/$1\/*$2*\//;' \
 		-e 's/^\/\*-((Copyright|=|----).*)$/\/* $1/;' \
-	      | indent | \
+	      | $INDENT | \
 	      perl -0 -np \
 		-e 's/\/\*\*INDENT-(ON|OFF)\*\*\/\n//g;' \
 	      | perl -np \
@@ -133,7 +136,7 @@ do
 	      | perl "$HERE"/su-filter.pl \
 	      > "$tmp"
 	  else
-	    expand "$j" | indent $INDENT_ARGS > "$tmp"
+	    expand "$j" | $INDENT $INDENT_ARGS > "$tmp"
 	  fi;
 	  if cmp -s "$tmp" "$j"; then
 	    if [ "$VERBOSE" = "true" ]; then