diff --git a/pkgs/applications/virtualization/xen/4.5.0.nix b/pkgs/applications/virtualization/xen/4.5.0.nix
deleted file mode 100644
index 887734ac6b9..00000000000
--- a/pkgs/applications/virtualization/xen/4.5.0.nix
+++ /dev/null
@@ -1,79 +0,0 @@
-{ callPackage, fetchurl, fetchgit, ... } @ args:
-
-let
-  # Xen 4.5.0
-  xenConfig = rec {
-    version = "4.5.0";
-    name = "xen-${version}";
-
-    src = fetchurl {
-      url = "http://bits.xensource.com/oss-xen/release/${version}/${name}.tar.gz";
-      sha256 = "0fvg00d596gh6cfm51xr8kj2mghcyivrf6np3dafnbldnbi41nsv";
-    };
-
-    # Sources needed to build the xen tools and tools/firmware.
-    firmwareGits =
-      [ # tag 1.7.5
-        { git = { name = "seabios";
-                  url = https://xenbits.xen.org/git-http/seabios.git;
-                  rev = "e51488c5f8800a52ac5c8da7a31b85cca5cc95d2";
-                  sha256 = "0jk54ybhmw97pzyhpm6jr2x99f702kbn0ipxv5qxcbynflgdazyb";
-                };
-          patches = [ ./0000-qemu-seabios-enable-ATA_DMA.patch ];
-        }
-        { git = { name = "ovmf";
-                  url = https://xenbits.xen.org/git-http/ovmf.git;
-                  rev = "447d264115c476142f884af0be287622cd244423";
-                  sha256 = "7086f882495a8be1497d881074e8f1005dc283a5e1686aec06c1913c76a6319b";
-                };
-        }
-      ];
-
-    toolsGits =
-      [ # tag qemu-xen-4.5.0
-        { git = { name = "qemu-xen";
-                  url = https://xenbits.xen.org/git-http/qemu-xen.git;
-                  rev = "1ebb75b1fee779621b63e84fefa7b07354c43a99";
-                  sha256 = "0yp9vmna3yl28vm5fkirghzhndaihmsm34fjzgr9sl6s46wx5yzg";
-                };
-        }
-        # tag xen-4.5.0
-        { git = { name = "qemu-xen-traditional";
-                  url = https://xenbits.xen.org/git-http/qemu-xen-traditional.git;
-                  rev = "b0d42741f8e9a00854c3b3faca1da84bfc69bf22";
-                  sha256 = "1lxlf1s81y5j0rhzzm1f4sbyrnbvd32vxiczs1qjcg6ls866vlki";
-                };
-        }
-        { git = { name = "xen-libhvm";
-                  url = https://github.com/ts468/xen-libhvm;
-                  rev = "442dcc4f6f4e374a51e4613532468bd6b48bdf63";
-                  sha256 = "9ba97c39a00a54c154785716aa06691d312c99be498ebbc00dc3769968178ba8";
-                };
-          description = ''
-            Helper library for reading ACPI and SMBIOS firmware values
-            from the host system for use with the HVM guest firmware
-            pass-through feature in Xen.
-            '';
-          #license = licenses.bsd2;
-        }
-      ];
-
-    xenserverPatches =
-      let
-        patches = {
-          url = https://github.com/ts468/xen-4.5.pg.git;
-          rev = "3442b65b490f43c817cbc53369220d0b1ab9b785";
-          sha256 = "31436c15def0a300b3ea1a63b2208c4a3bcbb143db5c6488d4db370b3ceeb845";
-        };
-      in ''
-        cp -r ${fetchgit patches}/master patches
-        quilt push -a
-        substituteInPlace tools/xenguest/Makefile --replace "_BSD_SOURCE" "_DEFAULT_SOURCE"
-      '';
-
-    xenPatches = [ ./0001-libxl-Spice-image-compression-setting-support-for-up.patch
-                   ./0002-libxl-Spice-streaming-video-setting-support-for-upst.patch
-                   ./0003-Add-qxl-vga-interface-support-for-upstream-qem.patch ];
-  };
-
-in callPackage ./generic.nix (args // { xenConfig=xenConfig; })
diff --git a/pkgs/applications/virtualization/xen/4.5.2.nix b/pkgs/applications/virtualization/xen/4.5.nix
similarity index 68%
rename from pkgs/applications/virtualization/xen/4.5.2.nix
rename to pkgs/applications/virtualization/xen/4.5.nix
index e0b13edb1f2..271ab7e7fe9 100644
--- a/pkgs/applications/virtualization/xen/4.5.2.nix
+++ b/pkgs/applications/virtualization/xen/4.5.nix
@@ -1,47 +1,41 @@
 { callPackage, fetchurl, fetchgit, ... } @ args:
 
 let
-  # Xen 4.5.2
+  # Xen 4.5.5
   xenConfig = rec {
-    version = "4.5.2";
+    version = "4.5.5";
     name = "xen-${version}";
 
     src = fetchurl {
       url = "http://bits.xensource.com/oss-xen/release/${version}/${name}.tar.gz";
-      sha256 = "1s7702zrxpsmx4vqvll4x2s762cfdiss4vgpx5s4jj7a9sn5v7jc";
+      sha256 = "1y74ms4yc3znf8jc3fgyq94va2y0pf7jh8m9pfqnpgklywqnw8g2";
     };
 
     # Sources needed to build the xen tools and tools/firmware.
     firmwareGits =
-      [ # tag 1.7.5
+      [
         { git = { name = "seabios";
                   url = https://xenbits.xen.org/git-http/seabios.git;
-                  rev = "e51488c5f8800a52ac5c8da7a31b85cca5cc95d2";
+                  rev = "rel-1.7.5";
                   sha256 = "0jk54ybhmw97pzyhpm6jr2x99f702kbn0ipxv5qxcbynflgdazyb";
                 };
           patches = [ ./0000-qemu-seabios-enable-ATA_DMA.patch ];
         }
-        { git = { name = "ovmf";
-                  url = https://xenbits.xen.org/git-http/ovmf.git;
-                  rev = "cb9a7ebabcd6b8a49dc0854b2f9592d732b5afbd";
-                  sha256 = "07zmdj90zjrzip74fvd4ss8n8njk6cim85s58mc6snxmqqv7gmcq";
-                };
-        }
       ];
 
     toolsGits =
-      [ # tag qemu-xen-4.5.2
+      [
         { git = { name = "qemu-xen";
                   url = https://xenbits.xen.org/git-http/qemu-xen.git;
-                  rev = "e5a1bb22cfb307db909dbd3404c48e5bbeb9e66d";
-                  sha256 = "00h6hc1y19y9wafxk01hvwm2j8lysz26wi2dnv8md76zxavg4maa";
+                  rev = "refs/tags/qemu-xen-${version}";
+                  sha256 = "014s755slmsc7xzy7qhk9i3kbjr2grxb5yznjp71dl6xxfvnday2";
                 };
         }
-        # tag xen-4.5.2
         { git = { name = "qemu-xen-traditional";
                   url = https://xenbits.xen.org/git-http/qemu-xen-traditional.git;
-                  rev = "dfe880e8d5fdc863ce6bbcdcaebaf918f8689cc0";
-                  sha256 = "07jwpxgk9ls5hma6vv1frnx1aczlvpddlgiyii9qmmlxxwjs21yj";
+                  # rev = "28c21388c2a32259cff37fc578684f994dca8c9f";
+                  rev = "refs/tags/xen-${version}";
+                  sha256 = "0n0ycxlf1wgdjkdl8l2w1i0zzssk55dfv67x8i6b2ima01r0k93r";
                 };
         }
         { git = { name = "xen-libhvm";
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 9450ef9915e..6282ce12939 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -15101,10 +15101,9 @@ in
 
   xdotool = callPackage ../tools/X11/xdotool { };
 
-  xen_4_5_0 = callPackage ../applications/virtualization/xen/4.5.0.nix { stdenv = overrideCC stdenv gcc49; };
-  xen_4_5_2 = callPackage ../applications/virtualization/xen/4.5.2.nix { stdenv = overrideCC stdenv gcc49; };
-  xen_xenServer = callPackage ../applications/virtualization/xen/4.5.0.nix { xenserverPatched = true; stdenv = overrideCC stdenv gcc49; };
-  xen = xen_4_5_2;
+  xen_4_5 = callPackage ../applications/virtualization/xen/4.5.nix { stdenv = overrideCC stdenv gcc49; };
+  xen_xenServer = callPackage ../applications/virtualization/xen/4.5.nix { xenserverPatched = true; stdenv = overrideCC stdenv gcc49; };
+  xen = xen_4_5;
 
   win-spice = callPackage ../applications/virtualization/driver/win-spice { };
   win-virtio = callPackage ../applications/virtualization/driver/win-virtio { };