diff --git a/processor/src/main/java/org/mapstruct/ap/internal/model/assignment/UpdateWrapper.java b/processor/src/main/java/org/mapstruct/ap/internal/model/assignment/UpdateWrapper.java
index b14e63df1..c63b488c9 100644
--- a/processor/src/main/java/org/mapstruct/ap/internal/model/assignment/UpdateWrapper.java
+++ b/processor/src/main/java/org/mapstruct/ap/internal/model/assignment/UpdateWrapper.java
@@ -78,6 +78,7 @@ public class UpdateWrapper extends AssignmentWrapper {
         imported.addAll( super.getImportTypes() );
         if ( targetImplementationType != null ) {
             imported.add( targetImplementationType );
+            imported.addAll( targetImplementationType.getTypeParameters() );
         }
         return imported;
     }
diff --git a/processor/src/test/java/org/mapstruct/ap/test/bugs/_955/CarMapper.java b/processor/src/test/java/org/mapstruct/ap/test/bugs/_955/CarMapper.java
new file mode 100644
index 000000000..afc8e16bc
--- /dev/null
+++ b/processor/src/test/java/org/mapstruct/ap/test/bugs/_955/CarMapper.java
@@ -0,0 +1,37 @@
+/**
+ *  Copyright 2012-2016 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._955;
+
+import org.mapstruct.Mapper;
+import org.mapstruct.MappingTarget;
+import org.mapstruct.ap.test.bugs._955.dto.Car;
+import org.mapstruct.ap.test.bugs._955.dto.SuperCar;
+import org.mapstruct.factory.Mappers;
+
+/**
+ *
+ * @author Sjaak Derksen
+ */
+@Mapper(uses = {CustomMapper.class})
+public interface CarMapper {
+
+    CarMapper INSTANCE = Mappers.getMapper( CarMapper.class );
+
+    SuperCar mapCar(Car source, @MappingTarget SuperCar destination);
+}
diff --git a/processor/src/test/java/org/mapstruct/ap/test/bugs/_955/CustomMapper.java b/processor/src/test/java/org/mapstruct/ap/test/bugs/_955/CustomMapper.java
new file mode 100644
index 000000000..604061762
--- /dev/null
+++ b/processor/src/test/java/org/mapstruct/ap/test/bugs/_955/CustomMapper.java
@@ -0,0 +1,34 @@
+/**
+ *  Copyright 2012-2016 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._955;
+
+import java.util.Map;
+import org.mapstruct.MappingTarget;
+import org.mapstruct.ap.test.bugs._955.dto.Person;
+
+/**
+ *
+ * @author Sjaak Derksen
+ */
+public class CustomMapper {
+
+    public Map<String, Person> merge(Map<String, Person> source, @MappingTarget Map<String, Person> destination) {
+        return destination;
+    }
+}
diff --git a/processor/src/test/java/org/mapstruct/ap/test/bugs/_955/Issue955Test.java b/processor/src/test/java/org/mapstruct/ap/test/bugs/_955/Issue955Test.java
new file mode 100644
index 000000000..72b70a7e9
--- /dev/null
+++ b/processor/src/test/java/org/mapstruct/ap/test/bugs/_955/Issue955Test.java
@@ -0,0 +1,41 @@
+/**
+ *  Copyright 2012-2016 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._955;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mapstruct.ap.test.bugs._955.dto.Car;
+import org.mapstruct.ap.test.bugs._955.dto.Person;
+import org.mapstruct.ap.test.bugs._955.dto.SuperCar;
+import org.mapstruct.ap.testutil.IssueKey;
+import org.mapstruct.ap.testutil.WithClasses;
+import org.mapstruct.ap.testutil.runner.AnnotationProcessorTestRunner;
+
+/**
+ *
+ * @author Sjaak Derksen
+ */
+@IssueKey( "955" )
+@RunWith(AnnotationProcessorTestRunner.class)
+@WithClasses( { CarMapper.class, CustomMapper.class, Car.class, SuperCar.class, Person.class } )
+public class Issue955Test {
+
+    @Test
+    public void shouldCompile() {   }
+}
diff --git a/processor/src/test/java/org/mapstruct/ap/test/bugs/_955/dto/Car.java b/processor/src/test/java/org/mapstruct/ap/test/bugs/_955/dto/Car.java
new file mode 100644
index 000000000..3ebfd78b6
--- /dev/null
+++ b/processor/src/test/java/org/mapstruct/ap/test/bugs/_955/dto/Car.java
@@ -0,0 +1,39 @@
+/**
+ *  Copyright 2012-2016 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._955.dto;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ *
+ * @author Sjaak Derksen
+ */
+public class Car {
+    private Map<String, Person> persons = new HashMap<String, Person>();
+
+    public Map<String, Person> getPersons() {
+        return persons;
+    }
+
+    public void setPersons(Map<String, Person> persons) {
+        this.persons = persons;
+    }
+
+}
diff --git a/processor/src/test/java/org/mapstruct/ap/test/bugs/_955/dto/Person.java b/processor/src/test/java/org/mapstruct/ap/test/bugs/_955/dto/Person.java
new file mode 100644
index 000000000..040eb2205
--- /dev/null
+++ b/processor/src/test/java/org/mapstruct/ap/test/bugs/_955/dto/Person.java
@@ -0,0 +1,27 @@
+/**
+ *  Copyright 2012-2016 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._955.dto;
+
+/**
+ *
+ * @author Sjaak Derksen
+ */
+public class Person {
+
+}
diff --git a/processor/src/test/java/org/mapstruct/ap/test/bugs/_955/dto/SuperCar.java b/processor/src/test/java/org/mapstruct/ap/test/bugs/_955/dto/SuperCar.java
new file mode 100644
index 000000000..bc2924b1a
--- /dev/null
+++ b/processor/src/test/java/org/mapstruct/ap/test/bugs/_955/dto/SuperCar.java
@@ -0,0 +1,39 @@
+/**
+ *  Copyright 2012-2016 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._955.dto;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ *
+ * @author Sjaak Derksen
+ */
+public class SuperCar {
+    private Map<String, Person> persons = new HashMap<String, Person>();
+
+    public Map<String, Person> getPersons() {
+        return persons;
+    }
+
+    public void setPersons(Map<String, Person> persons) {
+        this.persons = persons;
+    }
+
+}