diff --git a/pkgs/development/libraries/haskell/ekg-core/default.nix b/pkgs/development/libraries/haskell/ekg-core/default.nix
new file mode 100644
index 000000000000..6c332f832cd3
--- /dev/null
+++ b/pkgs/development/libraries/haskell/ekg-core/default.nix
@@ -0,0 +1,14 @@
+{ cabal, text, unorderedContainers }:
+
+cabal.mkDerivation (self: {
+  pname = "ekg-core";
+  version = "0.1.0.0";
+  sha256 = "19ghqj9zbb198d45bw7k9mlf2z57yq74wgbkp62b9li2ndbcpdzh";
+  buildDepends = [ text unorderedContainers ];
+  meta = {
+    homepage = "https://github.com/tibbe/ekg-core";
+    description = "Tracking of system metrics";
+    license = self.stdenv.lib.licenses.bsd3;
+    platforms = self.ghc.meta.platforms;
+  };
+})
diff --git a/pkgs/development/libraries/haskell/ekg/default.nix b/pkgs/development/libraries/haskell/ekg/default.nix
index 28ef546163a5..3f564a72a0a3 100644
--- a/pkgs/development/libraries/haskell/ekg/default.nix
+++ b/pkgs/development/libraries/haskell/ekg/default.nix
@@ -1,14 +1,14 @@
-{ cabal, aeson, filepath, network, snapCore, snapServer, text, time
-, transformers, unorderedContainers
+{ cabal, aeson, ekgCore, filepath, network, snapCore, snapServer
+, text, time, transformers, unorderedContainers
 }:
 
 cabal.mkDerivation (self: {
   pname = "ekg";
-  version = "0.3.1.4";
-  sha256 = "0hr9962yx463rq53xfqfm7vlv9izn47v3css3m6n4v694qlyz95i";
+  version = "0.4.0.0";
+  sha256 = "1w448w17yp80zmb27yl90k3gz0nx3wxj52488lclmiapr6q4fgp8";
   buildDepends = [
-    aeson filepath network snapCore snapServer text time transformers
-    unorderedContainers
+    aeson ekgCore filepath network snapCore snapServer text time
+    transformers unorderedContainers
   ];
   meta = {
     homepage = "https://github.com/tibbe/ekg";
diff --git a/pkgs/top-level/haskell-packages.nix b/pkgs/top-level/haskell-packages.nix
index f9cb9d0f3989..e92fec5f775d 100644
--- a/pkgs/top-level/haskell-packages.nix
+++ b/pkgs/top-level/haskell-packages.nix
@@ -1039,6 +1039,7 @@ let result = let callPackage = x : y : modifyPrio (newScope result.finalReturn x
   editline = self.editline_0_2_1_1;
 
   ekg = callPackage ../development/libraries/haskell/ekg {};
+  ekgCore = callPackage ../development/libraries/haskell/ekg-core {};
 
   elerea = callPackage ../development/libraries/haskell/elerea {};