diff --git a/headers/private/media/MediaConnection.h b/headers/private/media/MediaConnection.h
index eef78f8e54..9fb352f818 100644
--- a/headers/private/media/MediaConnection.h
+++ b/headers/private/media/MediaConnection.h
@@ -119,7 +119,7 @@ private:
 };
 
 
-class BMediaInput : public BMediaConnection {
+class BMediaInput : public virtual BMediaConnection {
 public:
 									BMediaInput();
 
@@ -149,7 +149,7 @@ private:
 };
 
 
-class BMediaOutput : public BMediaConnection {
+class BMediaOutput : public virtual BMediaConnection {
 public:
 									BMediaOutput();
 
diff --git a/src/kits/media/MediaClient.cpp b/src/kits/media/MediaClient.cpp
index 859fe3078d..d17b4a2f5f 100755
--- a/src/kits/media/MediaClient.cpp
+++ b/src/kits/media/MediaClient.cpp
@@ -147,9 +147,9 @@ BMediaClient::Connect(BMediaConnection* ourConnection,
 	CALLED();
 
 	if (ourConnection->IsOutput() && theirConnection.IsInput())
-		return _ConnectInput((BMediaOutput*)ourConnection, theirConnection);
+		return _ConnectInput(dynamic_cast<BMediaOutput*>(ourConnection), theirConnection);
 	else if (ourConnection->IsInput() && theirConnection.IsOutput())
-		return _ConnectOutput((BMediaInput*)ourConnection, theirConnection);
+		return _ConnectOutput(dynamic_cast<BMediaInput*>(ourConnection), theirConnection);
 
 	return B_ERROR;
 }