diff --git a/example/fibonacci_heap.cpp b/example/fibonacci_heap.cpp
index b602c1ad8..80c1881e4 100644
--- a/example/fibonacci_heap.cpp
+++ b/example/fibonacci_heap.cpp
@@ -41,7 +41,7 @@ int main()
             ICmp cmp(&w[0], std::less< float >());
             fibonacci_heap< int, ICmp > Q(N, cmp);
 
-            for (int c = 0; c < w.size(); ++c)
+            for (std::size_t c = 0; c < w.size(); ++c)
                 w[c] = c;
 #ifndef BOOST_NO_CXX98_RANDOM_SHUFFLE
             std::random_shuffle(w.begin(), w.end());
diff --git a/include/boost/pending/detail/disjoint_sets.hpp b/include/boost/pending/detail/disjoint_sets.hpp
index 9a91b294b..fc0038acc 100644
--- a/include/boost/pending/detail/disjoint_sets.hpp
+++ b/include/boost/pending/detail/disjoint_sets.hpp
@@ -55,8 +55,8 @@ namespace detail
     template < class ParentPA, class RankPA, class Vertex>
     inline void link_sets(ParentPA p, RankPA rank, Vertex i, Vertex j)
     {
-        assert(i == get(p, i));
-        assert(j == get(p, j));
+        assert(i == static_cast< Vertex >(get(p, i)));
+        assert(j == static_cast< Vertex >(get(p, j)));
         if (i == j)
             return;
         if (get(rank, i) > get(rank, j))
diff --git a/test/min_degree_empty.cpp b/test/min_degree_empty.cpp
index 462ab1b07..1585742fd 100644
--- a/test/min_degree_empty.cpp
+++ b/test/min_degree_empty.cpp
@@ -37,7 +37,7 @@ int main(int argc, char** argv)
 
     for (size_t k = 0; k < n; ++k)
     {
-        BOOST_TEST(o[io[k]] == k);
+        BOOST_TEST(o[io[k]] == static_cast< int >(k));
     }
 
     return boost::report_errors();