diff --git a/mumi/client.scm b/mumi/client.scm
index 797ec91..6ac69f9 100644
--- a/mumi/client.scm
+++ b/mumi/client.scm
@@ -292,8 +292,9 @@ ISSUE-NUMBER."
           (() (list))
           (cc (list (cons 'cc (string-join cc ", "))))))))
 
-(define (send-email patches)
-  "Send PATCHES via email."
+(define (send-email mumi-command patches)
+  "Send PATCHES via email. MUMI-COMMAND is the mumi program currently
+invoked."
   (if (current-issue-number)
       ;; If an issue is current, send patches to that issue's email
       ;; address.
@@ -301,7 +302,10 @@ ISSUE-NUMBER."
         (git-send-email (string-append (number->string issue-number)
                                        "@"
                                        (client-config 'debbugs-host))
-                        patches))
+                        patches
+                        (list (string-append "--header-cmd="
+                                             mumi-command
+                                             " git-send-email-headers"))))
       (match patches
         ;; If it's a single patch, send it to the patch email address
         ;; and be done with it
diff --git a/scripts/mumi.in b/scripts/mumi.in
index 8fb7cd4..5b98634 100644
--- a/scripts/mumi.in
+++ b/scripts/mumi.in
@@ -162,7 +162,7 @@
   (("new")
    (client:clear-current-issue!))
   (("send-email" . patches)
-   (client:send-email patches))
+   (client:send-email (car (program-arguments)) patches))
   (("git-send-email-headers" patch)
    (client:git-send-email-headers patch))
   (("mailer" . rest)
diff --git a/tests/client.scm b/tests/client.scm
index ced573b..d28bc1a 100644
--- a/tests/client.scm
+++ b/tests/client.scm
@@ -99,10 +99,13 @@ called with."
                                        (const 12345))
                                  client-config-stub)
              (cut (@@ (mumi client) send-email)
+                  "mumi"
                   (list "foo.patch" "bar.patch" "foobar.patch")))))))
 
 (test-equal "send patches to existing issue"
-  '(("git" "send-email" "--to=12345@example.com" "foo.patch" "bar.patch" "foobar.patch"))
+  '(("git" "send-email" "--to=12345@example.com"
+     "--header-cmd=mumi git-send-email-headers"
+     "foo.patch" "bar.patch" "foobar.patch"))
   (map (match-lambda
          ((command _) command))
        (trace-calls (var@@ (mumi client) call-with-input-pipe*)
@@ -114,6 +117,7 @@ called with."
                                  client-config-stub
                                  do-not-poll-server-for-issue-number)
              (cut (@@ (mumi client) send-email)
+                  "mumi"
                   (list "foo.patch" "bar.patch" "foobar.patch")))))))
 
 (test-equal "send single patch to new issue"
@@ -127,10 +131,13 @@ called with."
                                  client-config-stub
                                  do-not-poll-server-for-issue-number)
              (cut (@@ (mumi client) send-email)
+                  "mumi"
                   (list "foo.patch")))))))
 
 (test-equal "send single patch to existing issue"
-  '(("git" "send-email" "--to=12345@example.com" "foo.patch"))
+  '(("git" "send-email" "--to=12345@example.com"
+     "--header-cmd=mumi git-send-email-headers"
+     "foo.patch"))
   (map (match-lambda
          ((command _) command))
        (trace-calls (var@@ (mumi client) call-with-input-pipe*)
@@ -142,10 +149,13 @@ called with."
                                  client-config-stub
                                  do-not-poll-server-for-issue-number)
              (cut (@@ (mumi client) send-email)
+                  "mumi"
                   (list "foo.patch")))))))
 
 (test-equal "send patch to existing issue and Cc other participants"
-  '(("git" "send-email" "--to=12345@example.com" "foo.patch"))
+  '(("git" "send-email" "--to=12345@example.com"
+     "--header-cmd=mumi git-send-email-headers"
+     "foo.patch"))
   (map (match-lambda
          ((command _) command))
        (trace-calls (var@@ (mumi client) call-with-input-pipe*)
@@ -157,6 +167,7 @@ called with."
                                  client-config-stub
                                  do-not-poll-server-for-issue-number)
              (cut (@@ (mumi client) send-email)
+                  "mumi"
                   (list "foo.patch")))))))
 
 (test-end "client")
