diff --git a/spec/java_integration/fixtures/iface/SingleMethodIfaceWith2Args.java b/spec/java_integration/fixtures/iface/SingleMethodIfaceWith2Args.java
deleted file mode 100644
index dff80007e60..00000000000
--- a/spec/java_integration/fixtures/iface/SingleMethodIfaceWith2Args.java
+++ /dev/null
@@ -1,11 +0,0 @@
-package java_integration.fixtures.iface;
-
-public interface SingleMethodIfaceWith2Args {
-    public static class Caller {
-        public static void call(SingleMethodIfaceWith2Args iface) {
-            iface.doSome("hello", 42);
-        }
-    }
-
-    <V> void doSome(final String arg1, final V arg2);
-}
diff --git a/spec/java_integration/fixtures/iface/SingleMethodInterfaceWithArg.java b/spec/java_integration/fixtures/iface/SingleMethodInterfaceWithArg.java
new file mode 100644
index 00000000000..031b7e4cd5f
--- /dev/null
+++ b/spec/java_integration/fixtures/iface/SingleMethodInterfaceWithArg.java
@@ -0,0 +1,14 @@
+package java_integration.fixtures.iface;
+
+public interface SingleMethodInterfaceWithArg {
+    public static class Caller {
+        public static void call(SingleMethodInterfaceWithArg iface) {
+            call(42, iface);
+        }
+        public static <V> void call(V arg, SingleMethodInterfaceWithArg iface) {
+            iface.doSome(arg);
+        }
+    }
+
+    <V> void doSome(final V arg) ;
+}
diff --git a/spec/java_integration/interfaces/implementation_spec.rb b/spec/java_integration/interfaces/implementation_spec.rb
index ec65251456d..17dc41c9043 100644
--- a/spec/java_integration/interfaces/implementation_spec.rb
+++ b/spec/java_integration/interfaces/implementation_spec.rb
@@ -190,15 +190,16 @@ def callIt
   end
 
   it "passes correct arguments to proc .impl" do
-    Java::java.io.File.new('.').listFiles do |pathname|
-      pathname.should be_kind_of(java.io.File)
-      true
+    Java::java.io.File.new('.').list do |dir, name| # FilenameFilter
+      dir.should be_kind_of(java.io.File)
+      name.should be_kind_of(String)
+      true # boolean accept(File dir, String name)
     end
 
-    Java::java_integration.fixtures.iface.SingleMethodIfaceWith2Args::Caller.call do |arg1, arg2|
-      arg1.should == 'hello'
-      arg2.should == 42
-    end
+    caller = Java::java_integration.fixtures.iface.SingleMethodInterfaceWithArg::Caller
+
+    caller.call { |arg| arg.should == 42 }
+    caller.call('x') { |arg| arg.should == 'x' }
   end
 
   it "should maintain Ruby object equality when passed through Java and back" do