diff --git a/pkgs/applications/editors/emacs/macport.nix b/pkgs/applications/editors/emacs/macport.nix
index 3a573504c417..f991fe7ea666 100644
--- a/pkgs/applications/editors/emacs/macport.nix
+++ b/pkgs/applications/editors/emacs/macport.nix
@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, ncurses, pkgconfig, texinfo, libxml2, gnutls, gettext, autoconf, automake
+{ stdenv, fetchurl, ncurses, pkgconfig, texinfo, libxml2, gnutls, gettext, autoconf, automake, jansson
 , AppKit, Carbon, Cocoa, IOKit, OSAKit, Quartz, QuartzCore, WebKit
 , ImageCaptureCore, GSS, ImageIO # These may be optional
 }:
@@ -32,7 +32,7 @@ stdenv.mkDerivation rec {
 
   nativeBuildInputs = [ pkgconfig autoconf automake ];
 
-  buildInputs = [ ncurses libxml2 gnutls texinfo gettext
+  buildInputs = [ ncurses libxml2 gnutls texinfo gettext jansson
     AppKit Carbon Cocoa IOKit OSAKit Quartz QuartzCore WebKit
     ImageCaptureCore GSS ImageIO   # may be optional
   ];