diff --git a/src/IStorage.h b/src/IStorage.h
index f3ea50864..516f3e0e9 100644
--- a/src/IStorage.h
+++ b/src/IStorage.h
@@ -14,7 +14,7 @@ class IStorage
 public:
     typedef std::function<void(const char *, size_t, const void *, size_t)> callback;
 
-    virtual ~IStorage() {}
+    virtual ~IStorage();
 
     virtual void insert(const char *key, size_t cchKey, void *data, size_t cb) = 0;
     virtual void erase(const char *key, size_t cchKey) = 0;
@@ -25,7 +25,7 @@ public:
     virtual void beginWriteBatch() {} // NOP
     virtual void endWriteBatch() {} // NOP
 
-    virtual void flush();
+    virtual void flush() = 0;
 
     /* This is permitted to be a shallow clone */
     virtual const IStorage *clone() const = 0;
diff --git a/src/storage.cpp b/src/storage.cpp
index 0fc7de83c..cb095028a 100644
--- a/src/storage.cpp
+++ b/src/storage.cpp
@@ -1,5 +1,8 @@
 #include "server.h"
 
+
+IStorage::~IStorage() {}
+
 #ifdef USE_MEMKIND
 
 #include <stdlib.h>
@@ -11,6 +14,7 @@
 #include <inttypes.h>
 #include <fcntl.h>
 #include "storage.h"
+#include "IStorage.h"
 
 struct memkind *mkdisk = NULL;
 static const char *PMEM_DIR = NULL;