Sorry, I'm a bit late...
http://gwt-code-reviews.appspot.com/1420808/diff/6004/user/src/com/google/gwt/uibinder/rebind/TypeOracleUtils.java File user/src/com/google/gwt/uibinder/rebind/TypeOracleUtils.java (right): http://gwt-code-reviews.appspot.com/1420808/diff/6004/user/src/com/google/gwt/uibinder/rebind/TypeOracleUtils.java#newcode72 user/src/com/google/gwt/uibinder/rebind/TypeOracleUtils.java:72: if (paramType instanceof JPrimitiveType && argType instanceof JPrimitiveType) { Shouldn't it rather be paramType.isPrimitive() != null? http://gwt-code-reviews.appspot.com/1420808/ -- http://groups.google.com/group/Google-Web-Toolkit-Contributors