diff --git a/src/keystore.cpp b/src/keystore.cpp
index 5bf919cb..68f57e7e 100644
--- a/src/keystore.cpp
+++ b/src/keystore.cpp
@@ -33,6 +33,19 @@ bool CBasicKeyStore::AddKey(const CKey& key)
     return true;
 }
 
+bool CCryptoKeyStore::SetCrypted()
+{
+    CRITICAL_BLOCK(cs_KeyStore)
+    {
+        if (fUseCrypto)
+            return true;
+        if (!mapKeys.empty())
+            return false;
+        fUseCrypto = true;
+    }
+    return true;
+}
+
 std::vector<unsigned char> CCryptoKeyStore::GenerateNewKey()
 {
     RandAddSeedPerfmon();
diff --git a/src/keystore.h b/src/keystore.h
index d1e4985d..bbfac83d 100644
--- a/src/keystore.h
+++ b/src/keystore.h
@@ -65,15 +65,7 @@ private:
     bool fUseCrypto;
 
 protected:
-    bool SetCrypted()
-    {
-        if (fUseCrypto)
-            return true;
-        if (!mapKeys.empty())
-            return false;
-        fUseCrypto = true;
-        return true;
-    }
+    bool SetCrypted();
 
     // will encrypt previously unencrypted keys
     bool EncryptKeys(CKeyingMaterial& vMasterKeyIn);