diff --git a/java_gen/templates/_imports.java b/java_gen/templates/_imports.java
index 5b86571..a4c564c 100644
--- a/java_gen/templates/_imports.java
+++ b/java_gen/templates/_imports.java
@@ -1,6 +1,7 @@
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
+import java.util.Map;
 import org.openflow.protocol.*;
 import org.openflow.protocol.action.*;
 import org.openflow.protocol.meterband.*;