diff --git a/gtsam_unstable/slam/BiasedGPSFactor.h b/gtsam_unstable/slam/BiasedGPSFactor.h
index fc525f52a..c3f3f1d10 100644
--- a/gtsam_unstable/slam/BiasedGPSFactor.h
+++ b/gtsam_unstable/slam/BiasedGPSFactor.h
@@ -39,7 +39,7 @@ namespace gtsam {
   public:
 
     // shorthand for a smart pointer to a factor
-    typedef typename boost::shared_ptr<BiasedGPSFactor> shared_ptr;
+    typedef boost::shared_ptr<BiasedGPSFactor> shared_ptr;
 
     /** default constructor - only use for serialization */
     BiasedGPSFactor() {}