diff --git a/pkgs/development/libraries/haskell/psqueues/default.nix b/pkgs/development/libraries/haskell/psqueues/default.nix
new file mode 100644
index 00000000000..aea7f2f0950
--- /dev/null
+++ b/pkgs/development/libraries/haskell/psqueues/default.nix
@@ -0,0 +1,20 @@
+{ cabal, deepseq, hashable, HUnit, QuickCheck, tagged
+, testFramework, testFrameworkHunit, testFrameworkQuickcheck2
+}:
+
+cabal.mkDerivation (self: {
+  pname = "psqueues";
+  version = "0.1.1.0";
+  sha256 = "1w6i6cl9wfblbg8d06lffh4l5y42li9a27myyvwnzfv86z49s9cb";
+  buildDepends = [ deepseq hashable ];
+  testDepends = [
+    deepseq hashable HUnit QuickCheck tagged testFramework
+    testFrameworkHunit testFrameworkQuickcheck2
+  ];
+  meta = {
+    description = "Pure priority search queues";
+    license = self.stdenv.lib.licenses.bsd3;
+    platforms = self.ghc.meta.platforms;
+  };
+})
+
diff --git a/pkgs/development/libraries/haskell/slack-api/default.nix b/pkgs/development/libraries/haskell/slack-api/default.nix
new file mode 100644
index 00000000000..d5ed545a17d
--- /dev/null
+++ b/pkgs/development/libraries/haskell/slack-api/default.nix
@@ -0,0 +1,19 @@
+{ cabal, aeson, errors, HsOpenSSL, ioStreams, lens, lensAeson
+, monadLoops, mtl, network, opensslStreams, text, time
+, transformers, websockets, wreq
+}:
+
+cabal.mkDerivation (self: {
+  pname = "slack-api";
+  version = "0.2";
+  sha256 = "0gw6x57nnc16fm963l8z96cm4xapr4nbbmrbpx73k928a07fdq8j";
+  buildDepends = [
+    aeson errors HsOpenSSL ioStreams lens lensAeson monadLoops mtl
+    network opensslStreams text time transformers websockets wreq
+  ];
+  meta = {
+    description = "Bindings to the Slack RTM API";
+    license = self.stdenv.lib.licenses.mit;
+    platforms = self.ghc.meta.platforms;
+  };
+})
diff --git a/pkgs/top-level/haskell-packages.nix b/pkgs/top-level/haskell-packages.nix
index 5dbc6a5d4dd..c7084073f35 100644
--- a/pkgs/top-level/haskell-packages.nix
+++ b/pkgs/top-level/haskell-packages.nix
@@ -2112,6 +2112,8 @@ self : let callPackage = x : y : modifyPrio (newScope self x y); in
 
   PSQueue = callPackage ../development/libraries/haskell/PSQueue {};
 
+  psqueues = callPackage ../development/libraries/haskell/psqueues {};
+
   publicsuffixlist = callPackage ../development/libraries/haskell/publicsuffixlist {};
 
   pureMD5 = callPackage ../development/libraries/haskell/pureMD5 {};
@@ -2332,6 +2334,8 @@ self : let callPackage = x : y : modifyPrio (newScope self x y); in
 
   skein = callPackage ../development/libraries/haskell/skein {};
 
+  slackApi = callPackage ../development/libraries/haskell/slack-api {};
+
   smallcheck = callPackage ../development/libraries/haskell/smallcheck {};
 
   smtLib = callPackage ../development/libraries/haskell/smtLib {};