diff --git a/plugin/nix-exprs/sbtix.nix b/plugin/nix-exprs/sbtix.nix
index c286d12..8f9fed2 100644
--- a/plugin/nix-exprs/sbtix.nix
+++ b/plugin/nix-exprs/sbtix.nix
@@ -171,7 +171,7 @@ in rec {
           sbt stage
           mkdir -p $out/
           cp target/universal/stage/* $out/ -r
-          for p in $out/bin/*; do
+          for p in $(find $out/bin/* -executable); do
             wrapProgram "$p" --prefix PATH : ${jre}/bin
           done
         '';
diff --git a/plugin/src/main/scala/se/nullable/sbtix/CoursierArtifactFetcher.scala b/plugin/src/main/scala/se/nullable/sbtix/CoursierArtifactFetcher.scala
index f7309b3..9ebc7d8 100644
--- a/plugin/src/main/scala/se/nullable/sbtix/CoursierArtifactFetcher.scala
+++ b/plugin/src/main/scala/se/nullable/sbtix/CoursierArtifactFetcher.scala
@@ -185,7 +185,7 @@ class CoursierArtifactFetcher(logger: Logger, resolvers: Set[Resolver], credenti
               //only collect the http and https urls
              if (artifact.url.startsWith("http")) {
                 //reduce the number of tried and failed metaArtifacts by checking if Coursier succeeded in its download
-                val checkSum = FindArtifactsOfRepo.fetchChecksum(artifact.url, "-Meta- Artifact",f.toURI().toURL())
+                val checkSum = FindArtifactsOfRepo.fetchChecksum(artifact.url, "-Meta- Artifact",f.toURI().toURL()).get // TODO this might be expressed in a monad
                 metaArtifactCollector.add(MetaArtifact(artifact.url,checkSum))
              }
         }
diff --git a/plugin/src/main/scala/se/nullable/sbtix/FindArtifacts.scala b/plugin/src/main/scala/se/nullable/sbtix/FindArtifacts.scala
index 994e744..4ccf4e0 100644
--- a/plugin/src/main/scala/se/nullable/sbtix/FindArtifacts.scala
+++ b/plugin/src/main/scala/se/nullable/sbtix/FindArtifacts.scala
@@ -1,40 +1,56 @@
 package se.nullable.sbtix
 
+import java.io.{File, FileOutputStream, IOException}
 import java.net.URL
+import java.nio.file.Files
+import java.security.MessageDigest
 import java.util.concurrent.Semaphore
 
 import sbt.Logger
 
-import scala.sys.process._
+import scala.util.{Failure, Success, Try}
 
 object FindArtifactsOfRepo {
   private val semaphore = new Semaphore(4, false)
 
-  def fetchChecksum(originalUrl: String, artifactType: String, url: URL): String = {
-
-    val procLogger = sys.process.ProcessLogger {
-      mess =>
-        if (mess.startsWith("path is")) {
-          val modMess = mess.replace("path is ", "")
-          println(s"$artifactType ${originalUrl} => $modMess")
-        } else if (mess.startsWith("error: unable to download")) {
-          System.err.println(mess)
-        } else {
-          System.err.println(mess)
-        }
-    }
-
+  def fetchChecksum(originalUrl: String, artifactType: String, url: URL): Try[String] = {
     semaphore.acquireUninterruptibly()
-    val checksum = Seq("nix-prefetch-url", url.toString, "--type", "sha256").!!(procLogger).trim()
+    val checksum = calculateChecksum(url)
     semaphore.release()
+
     checksum
   }
+
+  private def calculateChecksum(url: URL): Try[String] = {
+    val tmpFile = File.createTempFile(s"sbtix-${url.toString}", ".tmp")
+    val path = tmpFile.toPath
+
+    try {
+      val hash = MessageDigest getInstance "SHA-256"
+      val input = url.openConnection.getInputStream
+      val w = new FileOutputStream(tmpFile)
+
+      Stream.continually(input.read).takeWhile(_ != -1).foreach(w.write)
+
+      hash update (Files readAllBytes path)
+      input.close()
+
+      Files.delete(path)
+
+      Success {
+        hash.digest() map { "%02X" format _ } mkString
+      }
+    } catch { case e: IOException =>
+      Files.delete(path)
+      Failure(e)
+    }
+  }
 }
 
 class FindArtifactsOfRepo(repoName: String, root: String) {
 
   def findArtifacts(logger: Logger, modules: Set[GenericModule]): Set[NixArtifact] = modules.flatMap { ga =>
-    val rootUrl = new URL(root);
+    val rootUrl = new URL(root)
 
     val authedRootURI = ga.authed(rootUrl) //authenticated version of the rootUrl
 
@@ -50,7 +66,7 @@ class FindArtifactsOfRepo(repoName: String, root: String) {
         repoName,
         calcUrl.toString.replace(authedRootURI.toString, "").stripPrefix("/"),
         calcUrl.toString,
-        FindArtifactsOfRepo.fetchChecksum(calcUrl.toString, "Artifact", artifactLocalFile.toURI.toURL))
+        FindArtifactsOfRepo.fetchChecksum(calcUrl.toString, "Artifact", artifactLocalFile.toURI.toURL).get)
     }
   }
 
diff --git a/sbtix-tool.nix b/sbtix-tool.nix
index acc010e..641b427 100644
--- a/sbtix-tool.nix
+++ b/sbtix-tool.nix
@@ -1,4 +1,4 @@
-{ callPackage, writeText, writeScriptBin, stdenv, sbt, nix-prefetch-scripts }:
+{ callPackage, writeText, writeScriptBin, stdenv, sbt }:
 let
   version = "0.2";
   versionSnapshotSuffix = "-SNAPSHOT";
@@ -30,8 +30,6 @@ let
   sbtixScript = writeScriptBin "sbtix" ''
     #! ${stdenv.shell}
 
-    export PATH=${nix-prefetch-scripts}/bin:$PATH
-
     # remove the ivy cache of sbtix so sbt retrieves from the sbtix nix repo. 
     # without this your version of sbtix may be overriden by the local ivy cache.
     echo "Deleting any cached sbtix plugins in '~/.ivy'. So the most recent version from nix is used."
diff --git a/tests/template-generation/run.sh b/tests/template-generation/run.sh
index 0b39b1d..b334fa4 100755
--- a/tests/template-generation/run.sh
+++ b/tests/template-generation/run.sh
@@ -2,6 +2,7 @@
 
 set -euxo pipefail
 
+cd "$(dirname "$0")"
 for f in {,project/}repo.nix; do
   if [[ -e "$f" ]]; then
     rm "$f"