diff --git a/ruby/src/main/java/com/google/protobuf/jruby/RubyFieldDescriptor.java b/ruby/src/main/java/com/google/protobuf/jruby/RubyFieldDescriptor.java
index 6987a587eddb1..931450fb6c9c0 100644
--- a/ruby/src/main/java/com/google/protobuf/jruby/RubyFieldDescriptor.java
+++ b/ruby/src/main/java/com/google/protobuf/jruby/RubyFieldDescriptor.java
@@ -38,6 +38,7 @@
 import org.jruby.*;
 import org.jruby.anno.JRubyClass;
 import org.jruby.anno.JRubyMethod;
+import org.jruby.runtime.Block;
 import org.jruby.runtime.ObjectAllocator;
 import org.jruby.runtime.ThreadContext;
 import org.jruby.runtime.builtin.IRubyObject;