diff --git a/Cache/BlockCache.cpp b/Cache/BlockCache.cpp
index 61462ed..3c24d2a 100644
--- a/Cache/BlockCache.cpp
+++ b/Cache/BlockCache.cpp
@@ -51,7 +51,8 @@ void BlockCache::read(unsigned block, void *bp)
 
 BlockCachePointer BlockCache::Create(BlockDevicePointer device)
 {
-    if (!device.get()) return BlockCachePointer();
+    // this just calls the device virtual function to create a cache.
+    if (!device) return BlockCachePointer();
     
     return device->createBlockCache();
 }
diff --git a/Cache/ConcreteBlockCache.cpp b/Cache/ConcreteBlockCache.cpp
index 5bf7ede..ef8c6b1 100644
--- a/Cache/ConcreteBlockCache.cpp
+++ b/Cache/ConcreteBlockCache.cpp
@@ -60,7 +60,10 @@ using ProFUSE::POSIXException;
 
 BlockCachePointer ConcreteBlockCache::Create(BlockDevicePointer device, unsigned size)
 {
-    return BlockCachePointer(new ConcreteBlockCache(device, size));
+    //return BlockCachePointer(new ConcreteBlockCache(device, size));
+    // constructor must be accessible to std::make_shared...
+    
+    return MAKE_SHARED(ConcreteBlockCache, device, size);
 }
 
 ConcreteBlockCache::ConcreteBlockCache(BlockDevicePointer device, unsigned size) :
diff --git a/Cache/MappedBlockCache.cpp b/Cache/MappedBlockCache.cpp
index 4a65fb1..bf0892b 100644
--- a/Cache/MappedBlockCache.cpp
+++ b/Cache/MappedBlockCache.cpp
@@ -21,7 +21,8 @@ using ProFUSE::POSIXException;
 
 BlockCachePointer MappedBlockCache::Create(BlockDevicePointer device, void *data)
 {
-    return BlockCachePointer(new MappedBlockCache(device, data));
+    //return BlockCachePointer(new MappedBlockCache(device, data));
+    return MAKE_SHARED(MappedBlockCache, device, data);
 }