diff --git a/pkgs/applications/virtualization/xen/generic.nix b/pkgs/applications/virtualization/xen/generic.nix
index 6d0344d4686..968d998792d 100644
--- a/pkgs/applications/virtualization/xen/generic.nix
+++ b/pkgs/applications/virtualization/xen/generic.nix
@@ -234,5 +234,6 @@ stdenv.mkDerivation (rec {
                     + withXenfiles (name: x: ''* ${name}: ${x.meta.description or "(No description)"}.'');
     platforms = [ "x86_64-linux" ];
     maintainers = with stdenv.lib.maintainers; [ eelco tstrobel oxij ];
+    license = stdenv.lib.licenses.gpl2;
   } // (config.meta or {});
 } // removeAttrs config [ "xenfiles" "buildInputs" "patches" "postPatch" "meta" ])
diff --git a/pkgs/development/libraries/harfbuzz/default.nix b/pkgs/development/libraries/harfbuzz/default.nix
index 383f7f60f9b..b3ab9c7881a 100644
--- a/pkgs/development/libraries/harfbuzz/default.nix
+++ b/pkgs/development/libraries/harfbuzz/default.nix
@@ -63,6 +63,7 @@ stdenv.mkDerivation {
     homepage = http://www.freedesktop.org/wiki/Software/HarfBuzz;
     downloadPage = "https://www.freedesktop.org/software/harfbuzz/release/";
     maintainers = [ maintainers.eelco ];
+    license = licenses.mit;
     platforms = with platforms; linux ++ darwin;
     inherit version;
     updateWalker = true;
diff --git a/pkgs/development/python-modules/pytest/default.nix b/pkgs/development/python-modules/pytest/default.nix
index 6146159ad0a..deb9cbdb7d0 100644
--- a/pkgs/development/python-modules/pytest/default.nix
+++ b/pkgs/development/python-modules/pytest/default.nix
@@ -37,8 +37,10 @@ buildPythonPackage rec {
   '';
 
   meta = with stdenv.lib; {
-    maintainers = with maintainers; [ domenkozar lovek323 madjar lsix ];
-    platforms = platforms.unix;
+    homepage = https://docs.pytest.org;
     description = "Framework for writing tests";
+    maintainers = with maintainers; [ domenkozar lovek323 madjar lsix ];
+    license = licenses.mit;
+    platforms = platforms.unix;
   };
 }
diff --git a/pkgs/tools/text/par/default.nix b/pkgs/tools/text/par/default.nix
index c7a686201b0..5f9ca5212d3 100644
--- a/pkgs/tools/text/par/default.nix
+++ b/pkgs/tools/text/par/default.nix
@@ -28,9 +28,11 @@ stdenv.mkDerivation {
   '';
 
 
-  meta = {
+  meta = with stdenv.lib; {
     homepage = http://www.nicemice.net/par/;
     description = "Paragraph reflow for email";
-    platforms = stdenv.lib.platforms.unix;
+    platforms = platforms.unix;
+    # See https://fedoraproject.org/wiki/Licensing/Par for license details
+    license = licenses.free;
   };
 }