diff --git a/pkgs/build-support/fetchmavenartifact/default.nix b/pkgs/build-support/fetchmavenartifact/default.nix
index b1d8593e72d4..0f3cd4e64dd6 100644
--- a/pkgs/build-support/fetchmavenartifact/default.nix
+++ b/pkgs/build-support/fetchmavenartifact/default.nix
@@ -37,13 +37,8 @@ assert (url == "") || (urls == []);
 assert (repos != []) || (url != "") || (urls != []);
 
 let
-  name_ =
-    lib.concatStrings [
-      (lib.replaceStrings ["."] ["_"] groupId) "_"
-      (lib.replaceStrings ["."] ["_"] artifactId) "-"
-      version
-    ];
-  suffix = if isNull classifier then "" else "-${classifier}";
+  pname = (lib.replaceStrings [ "." ] [ "_" ] groupId) + "_" + (lib.replaceStrings [ "." ] [ "_" ] artifactId);
+  suffix = lib.optionalString (classifier != null) "-${classifier}";
   filename = "${artifactId}-${version}${suffix}.jar";
   mkJarUrl = repoUrl:
     lib.concatStringsSep "/" [
@@ -59,13 +54,13 @@ let
     else map mkJarUrl repos;
   jar =
     fetchurl (
-      builtins.removeAttrs args ["groupId" "artifactId" "version" "classifier" "repos" "url" ]
-        // { urls = urls_; name = "${name_}.jar"; }
+      builtins.removeAttrs args [ "groupId" "artifactId" "version" "classifier" "repos" "url" ]
+      // { urls = urls_; name = "${pname}-${version}.jar"; }
     );
 in
   stdenv.mkDerivation {
-    name = name_;
-    phases = "installPhase fixupPhase";
+    inherit pname version;
+    dontUnpack = true;
     # By moving the jar to $out/share/java we make it discoverable by java
     # packages packages that mention this derivation in their buildInputs.
     installPhase = ''