diff --git a/source/Memory.cpp b/source/Memory.cpp
index 24ae91e4..36cbdb5a 100644
--- a/source/Memory.cpp
+++ b/source/Memory.cpp
@@ -246,7 +246,7 @@ static HANDLE g_hMemImage = NULL;	// NB. When not initialised, this handle is NU
 #endif
 
 BYTE __stdcall IO_Annunciator(WORD programcounter, WORD address, BYTE write, BYTE value, ULONG nCycles);
-void FreeMemImage(void);
+static void FreeMemImage(void);
 
 //=============================================================================