diff --git a/core/src/main/java/io/fabric8/maven/core/config/MappingConfig.java b/core/src/main/java/io/fabric8/maven/core/config/MappingConfig.java
index b07ada1349..df05eb42d0 100644
--- a/core/src/main/java/io/fabric8/maven/core/config/MappingConfig.java
+++ b/core/src/main/java/io/fabric8/maven/core/config/MappingConfig.java
@@ -22,7 +22,7 @@ public String[] getFilenamesAsArray() {
     }
 
     public boolean isValid() {
-        return kind != null &&  filenameTypes.length() > 0;
+        return kind != null &&  filenameTypes != null && filenameTypes.length() > 0;
     }
 
 }
diff --git a/plugin/src/main/java/io/fabric8/maven/plugin/mojo/build/ResourceMojo.java b/plugin/src/main/java/io/fabric8/maven/plugin/mojo/build/ResourceMojo.java
index 5dba72767d..9bb090d5a3 100644
--- a/plugin/src/main/java/io/fabric8/maven/plugin/mojo/build/ResourceMojo.java
+++ b/plugin/src/main/java/io/fabric8/maven/plugin/mojo/build/ResourceMojo.java
@@ -433,6 +433,9 @@ private void updateKindFilenameMappings() {
             for(MappingConfig mappingConfig : this.mappings) {
                 if (mappingConfig.isValid()) {
                     mappingKindFilename.put(mappingConfig.getKind(), Arrays.asList(mappingConfig.getFilenamesAsArray()));
+                } else {
+                    throw new IllegalArgumentException(String.format("Invalid mapping for Kind %s and Filename Types %s",
+                        mappingConfig.getKind(), mappingConfig.getFilenameTypes()));
                 }
             }
             KubernetesResourceUtil.updateKindFilenameMapper(mappingKindFilename);