diff --git a/Device/DiskImage.cpp b/Device/DiskImage.cpp
index 3820534..1c8d0cf 100644
--- a/Device/DiskImage.cpp
+++ b/Device/DiskImage.cpp
@@ -145,7 +145,7 @@ void ProDOSOrderDiskImage::Validate(MappedFile *f)
     
 }
 
-BlockCache *ProDOSOrderDiskImage::createBlockCache(unsigned size)
+BlockCache *ProDOSOrderDiskImage::createBlockCache()
 {
     return new MappedBlockCache(this, address());
 }
diff --git a/Device/DiskImage.h b/Device/DiskImage.h
index 2132c37..9bd87d9 100644
--- a/Device/DiskImage.h
+++ b/Device/DiskImage.h
@@ -62,7 +62,7 @@ public:
     static ProDOSOrderDiskImage *Open(MappedFile *);
 
     
-    virtual BlockCache *createBlockCache(unsigned size);
+    virtual BlockCache *createBlockCache();
     
 private:
     ProDOSOrderDiskImage(const char *name, bool readOnly);