kc3-lang/ftgl

diff --git a/include/FTLibrary.h b/include/FTLibrary.h
index 1e5ed6b..e4f53f5 100755
--- a/include/FTLibrary.h
+++ b/include/FTLibrary.h
@@ -34,7 +34,7 @@ class FTGL_EXPORT FTLibrary
          * 
          * @return  The global <code>FTLibrary</code> object.
          */
-        static FTLibrary& Instance();
+        static const FTLibrary& Instance();
 
         /**
          * Gets a pointer to the native Freetype library.
diff --git a/test/FTLibrary-Test.cpp b/test/FTLibrary-Test.cpp
index d614637..28a978c 100755
--- a/test/FTLibrary-Test.cpp
+++ b/test/FTLibrary-Test.cpp
@@ -20,8 +20,8 @@ class FTLibraryTest : public CppUnit::TestCase
 
         void testConstructor()
         {
-            FTLibrary& libraryOne = FTLibrary::Instance();
-            FTLibrary& libraryTwo = FTLibrary::Instance();
+            const FTLibrary& libraryOne = FTLibrary::Instance();
+            const FTLibrary& libraryTwo = FTLibrary::Instance();
             
             CPPUNIT_ASSERT( &libraryOne == &libraryTwo);
             CPPUNIT_ASSERT( &libraryOne == &FTLibrary::Instance());
@@ -30,7 +30,7 @@ class FTLibraryTest : public CppUnit::TestCase
         
         void testError()
         {
-            FTLibrary& library = FTLibrary::Instance();
+            const FTLibrary& library = FTLibrary::Instance();
             
             CPPUNIT_ASSERT( library.Error() == 0);
         }