diff --git a/pkgs/development/compilers/yap/default.nix b/pkgs/development/compilers/yap/default.nix
new file mode 100644
index 000000000000..27075d1cca63
--- /dev/null
+++ b/pkgs/development/compilers/yap/default.nix
@@ -0,0 +1,17 @@
+args:
+args.stdenv.mkDerivation rec {
+  name = "Yap-5.1.1";
+
+  src = args.fetchurl {
+    url = "http://downloads.sourceforge.net/yap/${name}.tar.gz";
+    sha256 = "0bajxmlla9gay4m4l7y7x6qldxzi0jcq2ykgpjk9liky7g5kbnya";
+  };
+
+  buildInputs =(with args; []);
+
+  meta = { 
+      description = "Yap Prolog System is a ISO-compatible high-performance Prolog compiler";
+      homepage = http://yap.sourceforge.net/;
+      license = "artistic";
+  };
+}
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 441b7db017f4..8a28e08bbe52 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -1606,6 +1606,10 @@ rec {
     inherit stdenv binutils;
   };
 
+  # prolog
+  yap = import ../development/compilers/yap {
+    inherit fetchurl stdenv;
+  };
 
   ### DEVELOPMENT / INTERPRETERS