diff --git a/include/etl/observer.h b/include/etl/observer.h
index 1cc9786a..1cd9b3f0 100644
--- a/include/etl/observer.h
+++ b/include/etl/observer.h
@@ -133,8 +133,9 @@ namespace etl
     //*****************************************************************
     /// Remove a particular observer from the list.
     ///\param observer A reference to the observer.
+    ///\return <b>true</b> if the observer was removed, <b>false</b> if not.
     //*****************************************************************
-    void remove_observer(TObserver& observer)
+    bool remove_observer(TObserver& observer)
     {
       // See if we have it in our list.
       typename Observer_List::iterator i_observer = std::find(observer_list.begin(),
@@ -146,6 +147,11 @@ namespace etl
       {
         // Erase it.
         observer_list.erase(i_observer);
+        return true;
+      }
+      else
+      {
+        return false;
       }
     }
 
diff --git a/include/etl/version.h b/include/etl/version.h
index 5c7e5d03..caaedbcf 100644
--- a/include/etl/version.h
+++ b/include/etl/version.h
@@ -37,10 +37,10 @@ SOFTWARE.
 /// Definitions of the ETL version
 ///\ingroup utilities
 
-#define ETL_VERSION "11.13.1"
+#define ETL_VERSION "11.13.2"
 #define ETL_VERSION_MAJOR 11
 #define ETL_VERSION_MINOR 13
-#define ETL_VERSION_PATCH  1
+#define ETL_VERSION_PATCH  2
 
 #endif
 
diff --git a/support/Release notes.txt b/support/Release notes.txt
index 94460ab2..e9202643 100644
--- a/support/Release notes.txt	
+++ b/support/Release notes.txt	
@@ -1,3 +1,8 @@
+===============================================================================
+11.13.2
+Protected destructor for some FSM classes.
+Observer's remove_observer returns bool.
+
 ===============================================================================
 11.13.1
 Fixed vector of pointer typedefs
diff --git a/test/test_observer.cpp b/test/test_observer.cpp
index f6efc6b4..b23a1359 100644
--- a/test/test_observer.cpp
+++ b/test/test_observer.cpp
@@ -424,7 +424,11 @@ namespace
 
       CHECK_THROW(observable.add_observer(observer5), etl::observer_list_full);
 
-      observable.remove_observer(observer3);
+      CHECK(observable.remove_observer(observer3));
+      CHECK_EQUAL(size_t(3), observable.number_of_observers());
+
+      // Try again.
+      CHECK(!observable.remove_observer(observer3));
       CHECK_EQUAL(size_t(3), observable.number_of_observers());
 
       observable.clear_observers();