diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000000000000000000000000000000000000..7731162b76b369cbaa16b610ea1b19939bd41f25
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,5 @@
+# Master
+
+- Fix bug in the `RealTuple::log` method: Calling `log(a,b)`returned `a-b`
+  instead of `b-a`.
+
diff --git a/dune/gfe/realtuple.hh b/dune/gfe/realtuple.hh
index e4bc4df8561ab9c5fff83bd529b29c7ffe97f61d..7f28cc851254a8ec6981ffda2d3ebbcf067ebb50 100644
--- a/dune/gfe/realtuple.hh
+++ b/dune/gfe/realtuple.hh
@@ -110,10 +110,11 @@ public:
     }
 
     /** \brief The logarithmic map
-     * Simply the difference vector for RealTuple
+     *
+     * \result A vector in the tangent space of a, viz: b-a
      * */
     static auto log(const RealTuple& a, const RealTuple& b) {
-        return a.data_ - b.data_;
+        return b.data_ - a.data_;
     }
 
 #if ADOLC_ADOUBLE_H
diff --git a/test/targetspacetest.cc b/test/targetspacetest.cc
index 34b5a285dafc26c0411a2f02dc4bbd218584c331..a677cd0e9f10f4b5e930d7bd11af03e937bb1272 100644
--- a/test/targetspacetest.cc
+++ b/test/targetspacetest.cc
@@ -355,8 +355,9 @@ void test()
 
 int main() try
 {
-//     test<RealTuple<double,1> >();
-//     test<RealTuple<double,3> >();
+    // Test the RealTuple class
+    test<RealTuple<double,1> >();
+    test<RealTuple<double,3> >();
     
     test<UnitVector<double,2> >();
     test<UnitVector<double,3> >();