diff --git a/src/java/io/bazel/rulesscala/jar/JarCreator.java b/src/java/io/bazel/rulesscala/jar/JarCreator.java
index c98c3f6ab..33d002a47 100644
--- a/src/java/io/bazel/rulesscala/jar/JarCreator.java
+++ b/src/java/io/bazel/rulesscala/jar/JarCreator.java
@@ -173,6 +173,16 @@ public void execute() throws IOException {
     }
   }
 
+  @Override
+  protected boolean ignoreFileName(String name) {
+    /*
+     * It does not make sense to copy signature files
+     * into a fat jar because the jar signature will
+     * be broken
+     */
+    return (name.endsWith(".DSA") || name.endsWith(".RSA"));
+  }
+
   public static void buildJar(String[] args) throws IOException {
     if (args.length < 1) {
       System.err.println("usage: CreateJar [-m manifest] output [root directories]");
diff --git a/src/java/io/bazel/rulesscala/jar/JarHelper.java b/src/java/io/bazel/rulesscala/jar/JarHelper.java
index d51956972..44707413a 100644
--- a/src/java/io/bazel/rulesscala/jar/JarHelper.java
+++ b/src/java/io/bazel/rulesscala/jar/JarHelper.java
@@ -177,17 +177,21 @@ protected void writeManifestEntry(byte[] content) throws IOException {
     }
   }
 
+  protected boolean ignoreFileName(String name) {
+    return false;
+  }
+
   /**
    * This copies the contents of jarFile into out
    * This is a static method to make it clear what is mutated (and it
    * was written by someone who really likes to minimize state changes).
    */
-  static private void copyJar(JarFile nameJf, Set<String> names, JarOutputStream out) throws IOException {
+  private void copyJar(JarFile nameJf, Set<String> names, JarOutputStream out) throws IOException {
     byte[] buffer = new byte[2048];
     for (Enumeration<JarEntry> e = nameJf.entries(); e.hasMoreElements();) {
       JarEntry existing = e.nextElement();
       String name = existing.getName();
-      if (!names.contains(name)) {
+      if (!(ignoreFileName(name) || names.contains(name))) {
         JarEntry outEntry = new JarEntry(name);
         outEntry.setTime(existing.getTime());
         outEntry.setSize(existing.getSize());
diff --git a/test/BUILD b/test/BUILD
index 08fe5dcd4..4ad2d2a17 100644
--- a/test/BUILD
+++ b/test/BUILD
@@ -374,3 +374,27 @@ scala_library(
     srcs = ["src/main/scala/scala/test/utf8/JavaClassWithUtf8.java",
             "src/main/scala/scala/test/utf8/ScalaClassWithUtf8.scala"]
     )
+
+# make sure making a fat jar strips signatures
+java_import(
+    name = "fakejar",
+    jars = ["fake_sig.jar"])
+
+scala_binary(
+    name = "ScalaBinary_with_fake",
+    srcs = ["ScalaBinary.scala"],
+    main_class = "scala.test.ScalaBinary",
+    deps = [":HelloLib", ":MacroTest", ":fakejar"],
+)
+
+py_binary(
+    name = "jar_lister",
+    srcs = ["jar_lister.py"]
+)
+
+sh_test(
+  name = "no_sig",
+  srcs = ["no_sigs.sh"],
+  args = ["$(location //test:jar_lister)", "$(location //test:ScalaBinary_with_fake_deploy.jar)"],
+  data = [":ScalaBinary_with_fake_deploy.jar", ":jar_lister"],
+)
diff --git a/test/fake_sig.jar b/test/fake_sig.jar
new file mode 100644
index 000000000..b76b2261c
Binary files /dev/null and b/test/fake_sig.jar differ
diff --git a/test/jar_lister.py b/test/jar_lister.py
new file mode 100644
index 000000000..3c3992bcc
--- /dev/null
+++ b/test/jar_lister.py
@@ -0,0 +1,5 @@
+import zipfile
+import sys
+
+for n in zipfile.ZipFile(sys.argv[1]).namelist():
+    print n
diff --git a/test/no_sigs.sh b/test/no_sigs.sh
new file mode 100755
index 000000000..756ecfd7c
--- /dev/null
+++ b/test/no_sigs.sh
@@ -0,0 +1,13 @@
+#!/bin/sh
+
+OUTPUT1=`$1 $2 | grep DSA`
+OUTPUT2=`$1 $2 | grep RSA`
+
+if [[ $OUTPUT1 ]]; then
+  echo $OUTPUT1
+  exit 1
+fi
+if [[ $OUTPUT2 ]]; then
+  echo $OUTPUT2
+  exit 1
+fi