diff --git a/gtsam/inference/Conditional.h b/gtsam/inference/Conditional.h
index fa75df83f..0e3e98361 100644
--- a/gtsam/inference/Conditional.h
+++ b/gtsam/inference/Conditional.h
@@ -20,6 +20,8 @@
 
 #include <gtsam/inference/Factor.h>
 
+#include <boost/range.hpp>
+
 #include <iostream>
 #include <list>
 
diff --git a/gtsam/inference/GenericSequentialSolver-inl.h b/gtsam/inference/GenericSequentialSolver-inl.h
index 1e48106e5..b5511dfd7 100644
--- a/gtsam/inference/GenericSequentialSolver-inl.h
+++ b/gtsam/inference/GenericSequentialSolver-inl.h
@@ -187,7 +187,7 @@ namespace gtsam {
 
     // Get rid of conditionals on variables that we want to marginalize out
     size_t nrMarginalized = bayesNet->size() - js.size();
-    for (int i = 0; i < nrMarginalized; i++)
+    for (size_t i = 0; i < nrMarginalized; i++)
       bayesNet->pop_front();
 
     return bayesNet;