diff --git a/include/cbm.h b/include/cbm.h
index 6ba1ef47e..e45ce1175 100644
--- a/include/cbm.h
+++ b/include/cbm.h
@@ -219,8 +219,10 @@ unsigned int cbm_load (const char* name, unsigned char device, void* data);
  * otherwise 0. "_oserror" contains an errorcode then (see table below).
  */
 
-unsigned char cbm_save (const char* name, unsigned char device,
-                        const void* data, unsigned int size);
+unsigned char __fastcall__ cbm_save (const char* name, 
+                                     unsigned char device,
+                                     const void* data, 
+                                     unsigned int size);
 /* Saves "size" bytes starting at "data" to a file.
  * Returns 0 if saving was successful, otherwise an errorcode (see table
  * below).
diff --git a/libsrc/cbm/cbm_save.c b/libsrc/cbm/cbm_save.c
index 8d74fc809..b88eed4ee 100644
--- a/libsrc/cbm/cbm_save.c
+++ b/libsrc/cbm/cbm_save.c
@@ -12,8 +12,10 @@
 
 /* saves a memory area from start to end-1 to a file.
  */
-unsigned char cbm_save(const char* name, unsigned char device,
-                       const void* data, unsigned int size)
+unsigned char __fastcall__ cbm_save (const char* name, 
+                                     unsigned char device,
+                                     const void* data, 
+                                     unsigned int size)
 {
     cbm_k_setlfs(0, device, 0);
     cbm_k_setnam(name);