diff --git a/CGAL_Core/include/CGAL/CORE/CoreAux.h b/CGAL_Core/include/CGAL/CORE/CoreAux.h
index 37eb1e3eb1f..2d2be9bea14 100644
--- a/CGAL_Core/include/CGAL/CORE/CoreAux.h
+++ b/CGAL_Core/include/CGAL/CORE/CoreAux.h
@@ -62,7 +62,7 @@ namespace CORE {
 const double relEps = (1.0 + std::ldexp(1.0, -52));
 
 /// CORE_DIAGFILE is used for all warning and error messages
-extern const char* CORE_DIAGFILE;
+const char* const CORE_DIAGFILE = "Core_Diagnostics";  // global file name
 
 /// template function returns the maximum value of two
 template <class T>
diff --git a/CGAL_Core/include/CGAL/CORE/CoreAux_impl.h b/CGAL_Core/include/CGAL/CORE/CoreAux_impl.h
index cfb72ece3c6..901ec82635c 100644
--- a/CGAL_Core/include/CGAL/CORE/CoreAux_impl.h
+++ b/CGAL_Core/include/CGAL/CORE/CoreAux_impl.h
@@ -194,9 +194,6 @@ int IntExponent(double d) {
 	return e-53;
 }
 
-/// CORE_DIAGFILE is file name for core_error(..) output.
-const char* CORE_DIAGFILE = "Core_Diagnostics";  // global file name 
-
 /// core_error is the method to write Core Library warning or error messages
 /** 	Both warnings and errors are written to a file called CORE_DIAGFILE.
  *	But errors are also written on std:cerr (similar to std::perror()).
diff --git a/CGAL_Core/include/CGAL/CORE/Impl.h b/CGAL_Core/include/CGAL/CORE/Impl.h
index 57d47a3f6e3..73bc8b1e7ae 100644
--- a/CGAL_Core/include/CGAL/CORE/Impl.h
+++ b/CGAL_Core/include/CGAL/CORE/Impl.h
@@ -40,6 +40,12 @@
   #define CORE_INLINE
 #endif
 
+#ifdef CGAL_HEADER_ONLY
+#define CGAL_INLINE_FUNCTION inline
+#else
+#define CGAL_INLINE_FUNCTION
+#endif
+
 // Macros for memory pool
 #ifdef CORE_DISABLE_MEMORY_POOL
   #define CORE_NEW(T)
@@ -51,9 +57,9 @@
   #define CORE_DELETE(T)  void operator delete( void *p, size_t );
 
   #define CORE_MEMORY_IMPL(T)                                            \
-    void *T::operator new( size_t size)                                  \
+    CGAL_INLINE_FUNCTION void *T::operator new( size_t size)             \
     { return MemoryPool<T>::global_allocator().allocate(size); }         \
-    void T::operator delete( void *p, size_t )                           \
+    CGAL_INLINE_FUNCTION void T::operator delete( void *p, size_t )      \
     { MemoryPool<T>::global_allocator().free(p); }
 #endif