diff --git a/pkgs/applications/networking/browsers/firefox/wrapper.nix b/pkgs/applications/networking/browsers/firefox/wrapper.nix
index 4c3647bd4481..dd4cb439c1fa 100644
--- a/pkgs/applications/networking/browsers/firefox/wrapper.nix
+++ b/pkgs/applications/networking/browsers/firefox/wrapper.nix
@@ -3,7 +3,7 @@
 ## various stuff that can be plugged in
 , flashplayer, hal-flash
 , MPlayerPlugin, ffmpeg, gst_all, xorg, libpulseaudio, libcanberra_gtk2
-, supportsJDK, jrePlugin, icedtea_web
+, jrePlugin, icedtea_web
 , trezor-bridge, bluejeans, djview4, adobe-reader
 , google_talk_plugin, fribid, gnome3/*.gnome_shell*/
 , esteidfirefoxplugin
@@ -36,6 +36,11 @@ let
       gssSupport = browser.gssSupport or false;
       jre = cfg.jre or false;
       icedtea = cfg.icedtea or false;
+      supportsJDK =
+        stdenv.system == "i686-linux" ||
+        stdenv.system == "x86_64-linux" ||
+        stdenv.system == "armv7l-linux" ||
+        stdenv.system == "aarch64-linux";
 
       plugins =
         assert !(jre && icedtea);
diff --git a/pkgs/development/compilers/oraclejdk/jdk-linux-base.nix b/pkgs/development/compilers/oraclejdk/jdk-linux-base.nix
index 554c322781fc..04fe377fab3b 100644
--- a/pkgs/development/compilers/oraclejdk/jdk-linux-base.nix
+++ b/pkgs/development/compilers/oraclejdk/jdk-linux-base.nix
@@ -1,10 +1,7 @@
 { productVersion
 , patchVersion
 , downloadUrl
-, sha256_i686
-, sha256_x86_64
-, sha256_armv7l
-, sha256_aarch64
+, sha256
 , jceName
 , jceDownloadUrl
 , sha256JCE
@@ -37,29 +34,19 @@
 , setJavaClassPath
 }:
 
-assert stdenv.system == "i686-linux"
-    || stdenv.system == "x86_64-linux"
-    || stdenv.system == "armv7l-linux"
-    || stdenv.system == "aarch64-linux";
 assert swingSupport -> xorg != null;
 
 let
-  abortArch = throw "Unsupported system: ${stdenv.system}";
 
   /**
    * The JRE libraries are in directories that depend on the CPU.
    */
-  architecture =
-    if stdenv.system == "i686-linux" then
-      "i386"
-    else if stdenv.system == "x86_64-linux" then
-      "amd64"
-    else if stdenv.system == "armv7l-linux" then
-      "arm"
-    else if stdenv.system == "aarch64-linux" then
-      "aarch64"
-    else
-      abortArch;
+  architecture = {
+    i686-linux    = "i386";
+    x86_64-linux  = "amd64";
+    armv7l-linux  = "arm";
+    aarch64-linux = "aarch64";
+  }.${stdenv.system};
 
   jce =
     if installjce then
@@ -84,33 +71,16 @@ let result = stdenv.mkDerivation rec {
   name =
     if installjdk then "oraclejdk-${productVersion}u${patchVersion}" else "oraclejre-${productVersion}u${patchVersion}";
 
-  src =
-    if stdenv.system == "i686-linux" then
-      requireFile {
-        name = "jdk-${productVersion}u${patchVersion}-linux-i586.tar.gz";
-        url = downloadUrl;
-        sha256 = sha256_i686;
-      }
-    else if stdenv.system == "x86_64-linux" then
-      requireFile {
-        name = "jdk-${productVersion}u${patchVersion}-linux-x64.tar.gz";
-        url = downloadUrl;
-        sha256 = sha256_x86_64;
-      }
-    else if stdenv.system == "armv7l-linux" then
-      requireFile {
-        name = "jdk-${productVersion}u${patchVersion}-linux-arm32-vfp-hflt.tar.gz";
-        url = downloadUrl;
-        sha256 = sha256_armv7l;
-      }
-    else if stdenv.system == "aarch64-linux" then
-      requireFile {
-        name = "jdk-${productVersion}u${patchVersion}-linux-arm64-vfp-hflt.tar.gz";
-        url = downloadUrl;
-        sha256 = sha256_aarch64;
-      }
-    else
-      abortArch;
+  src = requireFile {
+    name = {
+      i686-linux    = "jdk-${productVersion}u${patchVersion}-linux-i586.tar.gz";
+      x86_64-linux  = "jdk-${productVersion}u${patchVersion}-linux-x64.tar.gz";
+      armv7l-linux  = "jdk-${productVersion}u${patchVersion}-linux-arm32-vfp-hflt.tar.gz";
+      aarch64-linux = "jdk-${productVersion}u${patchVersion}-linux-arm64-vfp-hflt.tar.gz";
+    }.${stdenv.system};
+    url = downloadUrl;
+    sha256 = sha256.${stdenv.system};
+  };
 
   nativeBuildInputs = [ file ]
     ++ stdenv.lib.optional installjce unzip;
diff --git a/pkgs/development/compilers/oraclejdk/jdk8cpu-linux.nix b/pkgs/development/compilers/oraclejdk/jdk8cpu-linux.nix
index f3d032f7b1bb..096fe9dbb2ba 100644
--- a/pkgs/development/compilers/oraclejdk/jdk8cpu-linux.nix
+++ b/pkgs/development/compilers/oraclejdk/jdk8cpu-linux.nix
@@ -2,10 +2,10 @@ import ./jdk-linux-base.nix {
   productVersion = "8";
   patchVersion = "151";
   downloadUrl = http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html;
-  sha256_i686 = "0w1snn9hxwvdnk77frhdzbsm6v30v99dy5zmpy8ij7yxd57z6ql0";
-  sha256_x86_64 = "0zq2dxbxmshz080yskhc8y2wbqi0y0kl9girxjbb4rwk837010n7";
-  sha256_armv7l = "0fdkvg1al7g9lqbq10rlw400aqr0xxi2a802319sw5n0zipkrjic";
-  sha256_aarch64 = "1xva22cjjpwa95h7x3xzyymn1bgxp1q67j5j304kn6cqah4k31j1";
+  sha256.i686-linux = "0w1snn9hxwvdnk77frhdzbsm6v30v99dy5zmpy8ij7yxd57z6ql0";
+  sha256.x86_64-linux = "0zq2dxbxmshz080yskhc8y2wbqi0y0kl9girxjbb4rwk837010n7";
+  sha256.armv7l-linux = "0fdkvg1al7g9lqbq10rlw400aqr0xxi2a802319sw5n0zipkrjic";
+  sha256.aarch64-linux = "1xva22cjjpwa95h7x3xzyymn1bgxp1q67j5j304kn6cqah4k31j1";
   jceName = "jce_policy-8.zip";
   jceDownloadUrl = http://www.oracle.com/technetwork/java/javase/downloads/jce8-download-2133166.html;
   sha256JCE = "0n8b6b8qmwb14lllk2lk1q1ahd3za9fnjigz5xn65mpg48whl0pk";
diff --git a/pkgs/development/compilers/oraclejdk/jdk8psu-linux.nix b/pkgs/development/compilers/oraclejdk/jdk8psu-linux.nix
index 0703ec4a37ab..6c2816c8b87a 100644
--- a/pkgs/development/compilers/oraclejdk/jdk8psu-linux.nix
+++ b/pkgs/development/compilers/oraclejdk/jdk8psu-linux.nix
@@ -2,10 +2,10 @@ import ./jdk-linux-base.nix {
   productVersion = "8";
   patchVersion = "152";
   downloadUrl = http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html;
-  sha256_i686 = "0gjc7kcfx40f43z1w1qsn1fqxdz8d46wml2g11qgm55ishhv2q7w";
-  sha256_x86_64 = "1gv1348hrgna9l3sssv3g9jzs37y1lkx05xq83chav9z1hs3p2r1";
-  sha256_armv7l = "1w0hwslsd3z0kvb3z7gmbh20xsyiz73vglmdqz2108y7alim7arm";
-  sha256_aarch64 = "13qpxa8nxsnikmm7h6ysnsdqg5vl8j7hzfa8kgh20z8a17fhj9kk";
+  sha256.i686-linux = "0gjc7kcfx40f43z1w1qsn1fqxdz8d46wml2g11qgm55ishhv2q7w";
+  sha256.x86_64-linux = "1gv1348hrgna9l3sssv3g9jzs37y1lkx05xq83chav9z1hs3p2r1";
+  sha256.armv7l-linux = "1w0hwslsd3z0kvb3z7gmbh20xsyiz73vglmdqz2108y7alim7arm";
+  sha256.aarch64-linux = "13qpxa8nxsnikmm7h6ysnsdqg5vl8j7hzfa8kgh20z8a17fhj9kk";
   jceName = "jce_policy-8.zip";
   jceDownloadUrl = http://www.oracle.com/technetwork/java/javase/downloads/jce8-download-2133166.html;
   sha256JCE = "0n8b6b8qmwb14lllk2lk1q1ahd3za9fnjigz5xn65mpg48whl0pk";
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 5d3ea9a5588f..140e562b179d 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -6090,26 +6090,17 @@ with pkgs;
 
   jre8Plugin = lowPrio (pkgs.oraclejdk8distro false true);
 
-  supportsJDK =
-    system == "i686-linux" ||
-    system == "x86_64-linux" ||
-    system == "armv7l-linux" ||
-    system == "aarch64-linux";
-
   jdkdistro = oraclejdk8distro;
 
   oraclejdk8distro = installjdk: pluginSupport:
-    assert supportsJDK;
     (if pluginSupport then appendToName "with-plugin" else x: x)
       (callPackage ../development/compilers/oraclejdk/jdk8cpu-linux.nix { inherit installjdk pluginSupport; });
 
   oraclejdk8psu_distro = installjdk: pluginSupport:
-    assert supportsJDK;
     (if pluginSupport then appendToName "with-plugin" else x: x)
       (callPackage ../development/compilers/oraclejdk/jdk8psu-linux.nix { inherit installjdk pluginSupport; });
 
   oraclejdk9distro = packageType: pluginSupport:
-    assert supportsJDK;
     (if pluginSupport then appendToName "with-plugin" else x: x)
       (callPackage ../development/compilers/oraclejdk/jdk9-linux.nix { inherit packageType pluginSupport; });