diff --git a/.travis.yml b/.travis.yml
index b5ce7133..dd5429f2 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -56,4 +56,4 @@ after_success:
   - if [ "$COMPILER" = "g++-4.9" ]; then cd .. && ./build/bin/xlnt.test ; fi
   - if [ "$COMPILER" = "g++-4.9" ]; then export OLDWD=$(pwd) ; fi
   - if [ "$COMPILER" = "g++-4.9" ]; then cd "build/CMakeFiles/xlnt.static.dir$(pwd)" ; pwd ; fi
-  - if [ "$COMPILER" = "g++-4.9" ]; then coveralls --root $OLDWD --verbose -x ".cpp" --gcov-options '\-p' --exclude include --exclude third-party --exclude tests --exclude samples --exclude benchmarks ; fi
+  - if [ "$COMPILER" = "g++-4.9" ]; then coveralls --root $OLDWD --verbose -x ".cpp" --gcov-options '\-p' --exclude include --exclude third-party --exclude tests --exclude samples --exclude benchmarks --exclude-pattern "^source/.*/tests/*.hpp$" ; fi
diff --git a/include/xlnt/cell/index_types.hpp b/include/xlnt/cell/index_types.hpp
index a2378480..2b66c903 100644
--- a/include/xlnt/cell/index_types.hpp
+++ b/include/xlnt/cell/index_types.hpp
@@ -231,27 +231,27 @@ public:
     /// <summary>
     /// Return the result of adding rhs to this column.
     /// </summary>
-    friend column_t operator+(column_t lhs, const column_t& rhs);
+    friend XLNT_FUNCTION column_t operator+(column_t lhs, const column_t& rhs);
 
     /// <summary>
     /// Return the result of subtracing lhs by rhs column.
     /// </summary>
-    friend column_t operator-(column_t lhs, const column_t& rhs);
+    friend XLNT_FUNCTION column_t operator-(column_t lhs, const column_t& rhs);
 
     /// <summary>
     /// Return the result of multiply lhs by rhs column.
     /// </summary>
-    friend column_t operator*(column_t lhs, const column_t& rhs);
+    friend XLNT_FUNCTION column_t operator*(column_t lhs, const column_t& rhs);
 
     /// <summary>
     /// Return the result of divide lhs by rhs column.
     /// </summary>
-    friend column_t operator/(column_t lhs, const column_t& rhs);
+    friend XLNT_FUNCTION column_t operator/(column_t lhs, const column_t& rhs);
 
     /// <summary>
     /// Return the result of mod lhs by rhs column.
     /// </summary>
-    friend column_t operator%(column_t lhs, const column_t& rhs);
+    friend XLNT_FUNCTION column_t operator%(column_t lhs, const column_t& rhs);
 
     /// <summary>
     /// Add rhs to this column and return a reference to this column.
@@ -281,27 +281,27 @@ public:
     /// <summary>
     /// Return true if other is to the right of this column.
     /// </summary>
-    friend bool operator>(const column_t::index_t &left, const column_t &right);
+    friend XLNT_FUNCTION bool operator>(const column_t::index_t &left, const column_t &right);
 
     /// <summary>
     /// Return true if other is to the right of or equal to this column.
     /// </summary>
-    friend bool operator>=(const column_t::index_t &left, const column_t &right);
+    friend XLNT_FUNCTION bool operator>=(const column_t::index_t &left, const column_t &right);
 
     /// <summary>
     /// Return true if other is to the left of this column.
     /// </summary>
-    friend bool operator<(const column_t::index_t &left, const column_t &right);
+    friend XLNT_FUNCTION bool operator<(const column_t::index_t &left, const column_t &right);
 
     /// <summary>
     /// Return true if other is to the left of or equal to this column.
     /// </summary>
-    friend bool operator<=(const column_t::index_t &left, const column_t &right);
+    friend XLNT_FUNCTION bool operator<=(const column_t::index_t &left, const column_t &right);
 
     /// <summary>
     /// Swap the columns that left and right refer to.
     /// </summary>
-    friend void swap(column_t &left, column_t &right);
+    friend XLNT_FUNCTION void swap(column_t &left, column_t &right);
 
     /// <summary>
     /// Internal numeric value of this column index.
diff --git a/source/cell/tests/test_index_types.hpp b/source/cell/tests/test_index_types.hpp
index 7bafdb5d..624ca923 100644
--- a/source/cell/tests/test_index_types.hpp
+++ b/source/cell/tests/test_index_types.hpp
@@ -62,5 +62,10 @@ public:
         TS_ASSERT(!(c2 <= 3));
         TS_ASSERT(c1 >= 3);
         TS_ASSERT(!(c1 >= 4));
+
+        TS_ASSERT(4 >= c2);
+        TS_ASSERT(!(3 >= c2));
+        TS_ASSERT(3 <= c1);
+        TS_ASSERT(!(4 <= c1));
     }
 };