diff --git a/java_gen/templates/_imports.java b/java_gen/templates/_imports.java
index ef683e6..2d93b22 100644
--- a/java_gen/templates/_imports.java
+++ b/java_gen/templates/_imports.java
@@ -16,3 +16,4 @@
 import org.jboss.netty.buffer.ChannelBuffer;
 import org.jboss.netty.buffer.ChannelBuffers;
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;