diff --git a/pkgs/applications/misc/electrum/default.nix b/pkgs/applications/misc/electrum/default.nix
index 28b5f02e813a..0fde5c8644eb 100644
--- a/pkgs/applications/misc/electrum/default.nix
+++ b/pkgs/applications/misc/electrum/default.nix
@@ -2,11 +2,11 @@
 
 python2Packages.buildPythonApplication rec {
   name = "electrum-${version}";
-  version = "2.7.18";
+  version = "2.8.1";
 
   src = fetchurl {
     url = "https://download.electrum.org/${version}/Electrum-${version}.tar.gz";
-    sha256 = "1l9krc7hqhqrm5bwp999bpykkcq4958qwvx8v0l5mxcxw8k7fkab";
+    sha256 = "1398s9d8j04is24il2xjb6xkj666pj21bsr90xglpsmfa1js9z7g";
   };
 
   propagatedBuildInputs = with python2Packages; [
@@ -15,22 +15,22 @@ python2Packages.buildPythonApplication rec {
     jsonrpclib
     pbkdf2
     protobuf3_0
-    pyasn1
-    pyasn1-modules
+    pyaes
     pycrypto
     pyqt4
+    pysocks
     qrcode
     requests
-    slowaes
     tlslite
 
     # plugins
-    trezor
     keepkey
+    trezor
+
     # TODO plugins
-    # matplotlib
-    # btchip
     # amodem
+    # btchip
+    # matplotlib
   ];
 
   preBuild = ''
@@ -43,8 +43,11 @@ python2Packages.buildPythonApplication rec {
   postInstall = ''
     # Despite setting usr_share above, these files are installed under
     # $out/nix ...
-    mv $out/lib/python2.7/site-packages/nix/store/*/share $out
+    mv $out/lib/python2.7/site-packages/nix/store"/"*/share $out
     rm -rf $out/lib/python2.7/site-packages/nix
+
+    substituteInPlace $out/share/applications/electrum.desktop \
+      --replace "Exec=electrum %u" "Exec=$out/bin/electrum %u"
   '';
 
   doInstallCheck = true;
diff --git a/pkgs/development/python-modules/mnemonic.nix b/pkgs/development/python-modules/mnemonic.nix
new file mode 100644
index 000000000000..9f71fdb8e741
--- /dev/null
+++ b/pkgs/development/python-modules/mnemonic.nix
@@ -0,0 +1,21 @@
+{ lib, fetchurl, buildPythonPackage, pbkdf2 }:
+
+buildPythonPackage rec {
+  pname = "mnemonic";
+  version = "0.17";
+  name = "${pname}-${version}";
+
+  src = fetchurl {
+    url = "mirror://pypi/m/${pname}/${name}.tar.gz";
+    sha256 = "1hq6xb47jagfqf65iwcrh0065mj3521d2mxmahg7vfraihqyqdjn";
+  };
+
+  propagatedBuildInputs = [ pbkdf2 ];
+
+  meta = {
+    description = "Implementation of Bitcoin BIP-0039";
+    homepage = https://github.com/trezor/python-mnemonic;
+    license = lib.licenses.mit;
+    maintainers = with lib.maintainers; [ np ];
+  };
+}
diff --git a/pkgs/development/python-modules/pyaes.nix b/pkgs/development/python-modules/pyaes.nix
new file mode 100644
index 000000000000..c2feb2e239c7
--- /dev/null
+++ b/pkgs/development/python-modules/pyaes.nix
@@ -0,0 +1,18 @@
+{ lib, fetchPypi, buildPythonPackage }:
+
+buildPythonPackage rec {
+  pname = "pyaes";
+  version = "1.6.0";
+  name = "${pname}-${version}";
+
+  src = fetchPypi {
+    inherit pname version;
+    sha256 = "0bp9bjqy1n6ij1zb86wz9lqa1dhla8qr1d7w2kxyn7jbj56sbmcw";
+  };
+
+  meta = {
+    description = "Pure-Python AES";
+    license = lib.licenses.mit;
+    homepage = https://github.com/ricmoo/pyaes;
+  };
+}
diff --git a/pkgs/development/python-modules/trezor.nix b/pkgs/development/python-modules/trezor.nix
new file mode 100644
index 000000000000..36bf0c15de25
--- /dev/null
+++ b/pkgs/development/python-modules/trezor.nix
@@ -0,0 +1,26 @@
+{ lib, fetchurl, buildPythonPackage, protobuf3_0, hidapi, ecdsa, mnemonic }:
+
+buildPythonPackage rec {
+  pname = "trezor";
+  version = "0.7.12";
+  name = "${pname}-${version}";
+
+  src = fetchurl {
+    url = "mirror://pypi/t/${pname}/${name}.tar.gz";
+    sha256 = "0ryqdk13x60qq5s68i9dfc1na4dka66kdxqycxignzg9k9ykaa8g";
+  };
+
+  propagatedBuildInputs = [ protobuf3_0 hidapi ];
+
+  buildInputs = [ ecdsa mnemonic ];
+
+  # There are no actual tests: "ImportError: No module named tests"
+  doCheck = false;
+
+  meta = {
+    description = "Python library for communicating with TREZOR Bitcoin Hardware Wallet";
+    homepage = https://github.com/trezor/python-trezor;
+    license = lib.licenses.gpl3;
+    maintainers = with lib.maintainers; [ np ];
+  };
+}
diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index 11ebfad988c2..9260b8e73faa 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -289,6 +289,8 @@ in {
 
   plantuml = callPackage ../tools/misc/plantuml { };
 
+  pyaes = callPackage ../development/python-modules/pyaes.nix { };
+
   pyatspi = if isPy3k then callPackage ../development/python-modules/pyatspi { } else throw "pyatspi not supported for interpreter ${python.executable}";
 
   pycairo = callPackage ../development/python-modules/pycairo { };
@@ -30780,48 +30782,9 @@ EOF
     };
   };
 
-  mnemonic = buildPythonPackage rec{
-    version = "0.12";
-    name = "mnemonic-${version}";
+  mnemonic = callPackage ../development/python-modules/mnemonic.nix { };
 
-    src = pkgs.fetchurl {
-      url = "mirror://pypi/m/mnemonic/${name}.tar.gz";
-      sha256 = "0j5jm4v54135qqw455fw4ix2mhxhzjqvxji9gqkpxagk31cvbnj4";
-    };
-
-    propagatedBuildInputs = with self; [ pbkdf2 ];
-
-    meta = {
-      description = "Implementation of Bitcoin BIP-0039";
-      homepage = https://github.com/trezor/python-mnemonic;
-      license = licenses.mit;
-      maintainers = with maintainers; [ np ];
-    };
-  };
-
-  trezor = buildPythonPackage rec{
-    version = "0.7.4";
-    name = "trezor-${version}";
-
-    src = pkgs.fetchurl {
-      url = "mirror://pypi/t/trezor/${name}.tar.gz";
-      sha256 = "18nr76jkdg24sb3r8cfbiq12b95gnh0amc0r1wx9mmg3pwq6jx6y";
-    };
-
-    propagatedBuildInputs = with self; [ protobuf3_0 hidapi ];
-
-    buildInputs = with self; [ ecdsa mnemonic ];
-
-    # There are no actual tests: "ImportError: No module named tests"
-    doCheck = false;
-
-    meta = {
-      description = "Python library for communicating with TREZOR Bitcoin Hardware Wallet";
-      homepage = https://github.com/trezor/python-trezor;
-      license = licenses.gpl3;
-      maintainers = with maintainers; [ np ];
-    };
-  };
+  trezor = callPackage ../development/python-modules/trezor.nix { };
 
   keepkey = buildPythonPackage rec{
     version = "0.7.3";