diff --git a/processor/src/test/java/org/mapstruct/ap/test/bugs/_306/Issue306Mapper.java b/processor/src/test/java/org/mapstruct/ap/test/bugs/_306/Issue306Mapper.java
new file mode 100644
index 000000000..c22fbe7b2
--- /dev/null
+++ b/processor/src/test/java/org/mapstruct/ap/test/bugs/_306/Issue306Mapper.java
@@ -0,0 +1,41 @@
+/**
+ *  Copyright 2012-2014 Gunnar Morling (http://www.gunnarmorling.de/)
+ *  and/or other contributors as indicated by the @authors tag. See the
+ *  copyright.txt file in the distribution for a full listing of all
+ *  contributors.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.mapstruct.ap.test.bugs._306;
+
+import java.util.Set;
+
+import org.mapstruct.Mapper;
+import org.mapstruct.TargetType;
+import org.mapstruct.factory.Mappers;
+
+@Mapper
+public abstract class Issue306Mapper {
+
+    public static final Issue306Mapper INSTANCE = Mappers.getMapper( Issue306Mapper.class );
+
+    public abstract Source targetToSource(Target target);
+
+    protected void dummy1( Set<String> arg ) {
+        throw new RuntimeException();
+    }
+
+    protected Set<Long> dummy2( Object object,  @TargetType Class<?> clazz ) {
+        throw new RuntimeException();
+    }
+}
diff --git a/processor/src/test/java/org/mapstruct/ap/test/bugs/_306/Issue306Test.java b/processor/src/test/java/org/mapstruct/ap/test/bugs/_306/Issue306Test.java
new file mode 100644
index 000000000..e6f69ff96
--- /dev/null
+++ b/processor/src/test/java/org/mapstruct/ap/test/bugs/_306/Issue306Test.java
@@ -0,0 +1,40 @@
+/**
+ *  Copyright 2012-2014 Gunnar Morling (http://www.gunnarmorling.de/)
+ *  and/or other contributors as indicated by the @authors tag. See the
+ *  copyright.txt file in the distribution for a full listing of all
+ *  contributors.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.mapstruct.ap.test.bugs._306;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mapstruct.ap.testutil.IssueKey;
+import org.mapstruct.ap.testutil.WithClasses;
+import org.mapstruct.ap.testutil.runner.AnnotationProcessorTestRunner;
+
+/**
+ * Reproducer for https://github.com/mapstruct/mapstruct/issues/306.
+ *
+ * @author Sjaak Derksen
+ */
+@IssueKey( "306" )
+@RunWith(AnnotationProcessorTestRunner.class)
+public class Issue306Test {
+
+    @Test
+    @WithClasses( { Issue306Mapper.class, Source.class, Target.class } )
+    public void shouldForgeNewIterableMappingMethod() {
+    }
+}
diff --git a/processor/src/test/java/org/mapstruct/ap/test/bugs/_306/Source.java b/processor/src/test/java/org/mapstruct/ap/test/bugs/_306/Source.java
new file mode 100644
index 000000000..59e812ae8
--- /dev/null
+++ b/processor/src/test/java/org/mapstruct/ap/test/bugs/_306/Source.java
@@ -0,0 +1,35 @@
+/**
+ *  Copyright 2012-2014 Gunnar Morling (http://www.gunnarmorling.de/)
+ *  and/or other contributors as indicated by the @authors tag. See the
+ *  copyright.txt file in the distribution for a full listing of all
+ *  contributors.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.mapstruct.ap.test.bugs._306;
+
+import java.util.Set;
+
+
+public class Source {
+
+    private Set<String> fooSet;
+
+    public Set<String> getFooSet() {
+        return fooSet;
+    }
+
+    public void setFooSet(Set<String> fooSet) {
+        this.fooSet = fooSet;
+    }
+}
diff --git a/processor/src/test/java/org/mapstruct/ap/test/bugs/_306/Target.java b/processor/src/test/java/org/mapstruct/ap/test/bugs/_306/Target.java
new file mode 100644
index 000000000..d3c45074a
--- /dev/null
+++ b/processor/src/test/java/org/mapstruct/ap/test/bugs/_306/Target.java
@@ -0,0 +1,34 @@
+/**
+ *  Copyright 2012-2014 Gunnar Morling (http://www.gunnarmorling.de/)
+ *  and/or other contributors as indicated by the @authors tag. See the
+ *  copyright.txt file in the distribution for a full listing of all
+ *  contributors.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.mapstruct.ap.test.bugs._306;
+
+import java.util.Set;
+
+public class Target {
+
+    private Set<Long> fooSet;
+
+    public Set<Long> getFooSet() {
+        return fooSet;
+    }
+
+    public void setFooSet(Set<Long> fooSet) {
+        this.fooSet = fooSet;
+    }
+}
diff --git a/processor/src/test/java/org/mapstruct/ap/test/collection/forged/CollectionMapper.java b/processor/src/test/java/org/mapstruct/ap/test/collection/forged/CollectionMapper.java
index fc52c88cb..7462a4f19 100644
--- a/processor/src/test/java/org/mapstruct/ap/test/collection/forged/CollectionMapper.java
+++ b/processor/src/test/java/org/mapstruct/ap/test/collection/forged/CollectionMapper.java
@@ -18,27 +18,14 @@
  */
 package org.mapstruct.ap.test.collection.forged;
 
-import java.util.Set;
 import org.mapstruct.Mapper;
-import org.mapstruct.TargetType;
 import org.mapstruct.factory.Mappers;
 
 @Mapper
-public abstract class CollectionMapper {
+public interface CollectionMapper {
 
-    public static final CollectionMapper INSTANCE = Mappers.getMapper( CollectionMapper.class );
+    CollectionMapper INSTANCE = Mappers.getMapper( CollectionMapper.class );
 
-    public abstract Target sourceToTarget(Source source);
-    public abstract Source targetToSource(Target target);
-
-
-    // this method is added to reproduce issue 306
-    protected void dummy1( Set<String> arg ) {
-        throw new RuntimeException();
-    }
-
-    // this method is added to reproduce issue 306
-    protected Set<Long> dummy2( Object object,  @TargetType Class clazz ) {
-        throw new RuntimeException();
-    }
+    Target sourceToTarget(Source source);
+    Source targetToSource(Target target);
 }
diff --git a/processor/src/test/java/org/mapstruct/ap/test/collection/forged/CollectionMappingTest.java b/processor/src/test/java/org/mapstruct/ap/test/collection/forged/CollectionMappingTest.java
index 13a2073f2..828f1b6b6 100644
--- a/processor/src/test/java/org/mapstruct/ap/test/collection/forged/CollectionMappingTest.java
+++ b/processor/src/test/java/org/mapstruct/ap/test/collection/forged/CollectionMappingTest.java
@@ -34,11 +34,10 @@ import org.mapstruct.ap.util.Collections;
  *
  * @author Sjaak Derksen
  */
-@IssueKey("4, 306")
+@IssueKey( "4" )
 @RunWith(AnnotationProcessorTestRunner.class)
 public class CollectionMappingTest {
 
-
     @Test
     @WithClasses({ CollectionMapper.class, Source.class, Target.class })
     public void shouldForgeNewIterableMappingMethod() {
@@ -59,13 +58,13 @@ public class CollectionMappingTest {
     @WithClasses({ CollectionMapper.class, Source.class, Target.class })
     public void shouldForgeNewMapMappingMethod() {
 
-        Map sourceMap = ImmutableMap.<String, Long>builder().put( "rabbit", 1L ).build();
+        Map<String, Long> sourceMap = ImmutableMap.<String, Long>builder().put( "rabbit", 1L ).build();
         Source source = new Source();
         source.setBarMap( sourceMap );
 
         Target target = CollectionMapper.INSTANCE.sourceToTarget( source );
         assertThat( target ).isNotNull();
-        Map targetMap = ImmutableMap.<String, String>builder().put( "rabbit", "1" ).build();
+        Map<String, String> targetMap = ImmutableMap.<String, String>builder().put( "rabbit", "1" ).build();
         assertThat( target.getBarMap() ).isEqualTo( targetMap );
 
         Source source2 = CollectionMapper.INSTANCE.targetToSource( target );