diff --git a/GNUmakefile b/GNUmakefile
index 9430a18..b8d70d4 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -28,7 +28,7 @@ maddr magrep mdeliver mexport mflag mflow mgenmid mhdr mpick mscan msed mshow \
 maddr magrep mexport mflag mgenmid mhdr mlist mpick mscan msed mseq mshow msort \
   mthread : seq.o slurp.o
 maddr magrep mflow mhdr mpick mscan mshow : rfc2047.o
-magrep mflow mshow : rfc2045.o
+magrep mflow mhdr mshow : rfc2045.o
 mshow : filter.o safe_u8putstr.o rfc2231.o pipeto.o
 mscan : pipeto.o
 msort : mystrverscmp.o
diff --git a/man/mhdr.1 b/man/mhdr.1
index 3046e3b..f34d9b9 100644
--- a/man/mhdr.1
+++ b/man/mhdr.1
@@ -6,7 +6,7 @@
 .Nd show mail headers
 .Sh SYNOPSIS
 .Nm
-.Op Fl h Ar header
+.Op Fl h Ar header Op Fl p Ar parameter
 .Op Fl d
 .Op Fl H
 .Op Fl M
@@ -31,6 +31,10 @@ The options are as follows:
 .It Fl h Ar header
 Only print the values of the headers in the colon-separated list
 .Ar header .
+.It Fl p Ar parameter
+Extract a particular RFC 2045
+.Ar parameter
+from the specified headers.
 .It Fl d
 Decode the headers according to RFC 2047.
 .It Fl H
@@ -55,6 +59,13 @@ and >1 if an error occurs.
 .Rs
 .%A N. Freed
 .%A N. Borenstein
+.%D November 1996
+.%R RFC 2045
+.%T Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies
+.Re
+.Rs
+.%A N. Freed
+.%A N. Borenstein
 .%B MIME (Multipurpose Internet Mail Extensions) Part Three: Message Header Extensions for Non-ASCII Text
 .%R RFC 2047
 .%D November 1996
diff --git a/mhdr.c b/mhdr.c
index cc49c22..73d76f9 100644
--- a/mhdr.c
+++ b/mhdr.c
@@ -12,6 +12,7 @@
 #include "blaze822.h"
 
 static char *hflag;
+static char *pflag;
 static int Aflag;
 static int Dflag;
 static int Hflag;
@@ -100,6 +101,16 @@ print_decode_header(char *s)
 void
 print_header(char *v)
 {
+	if (pflag) {
+		char *s, *se;
+		if (blaze822_mime_parameter(v, pflag, &s, &se)) {
+			*se = 0;
+			v = s;
+		} else {
+			return;
+		}
+	}
+
 	status = 0;
 
 	if (Hflag && !Aflag)
@@ -188,9 +199,10 @@ int
 main(int argc, char *argv[])
 {
 	int c;
-	while ((c = getopt(argc, argv, "h:ADHMd")) != -1)
+	while ((c = getopt(argc, argv, "h:p:ADHMd")) != -1)
 		switch (c) {
 		case 'h': hflag = optarg; break;
+		case 'p': pflag = optarg; break;
 		case 'A': Aflag = 1; break;
 		case 'D': Dflag = 1; break;
 		case 'H': Hflag = 1; break;
@@ -198,7 +210,7 @@ main(int argc, char *argv[])
 		case 'd': dflag = 1; break;
 		default:
 			fprintf(stderr,
-"Usage: mhdr [-h header] [-d] [-H] [-M] [-A|-D] [msgs...]\n");
+"Usage: mhdr [-h header [-p parameter]] [-d] [-H] [-M] [-A|-D] [msgs...]\n");
 			exit(2);
 		}