diff --git a/src/DimServices/DimServices.cxx b/src/DimServices/DimServices.cxx
index b837445..e32e17b 100644
--- a/src/DimServices/DimServices.cxx
+++ b/src/DimServices/DimServices.cxx
@@ -104,14 +104,18 @@ void StringRpcServer::rpcHandler()
   alfDebugLog.info("Request received on %s : %s",mServiceName.c_str(),getString());
   try {
     auto returnValue = mCallback(std::string(getString()));
-    setDataString(makeSuccessString(returnValue), *this);
+    auto reply = makeSuccessString(returnValue);
+    mDimBuffer = toCharBuffer(reply, true); // keep buffer alive
+    setData(mDimBuffer.data(), mDimBuffer.size());
     rtrim(returnValue);
     alfDebugLog.info("Request completed: %s", returnValue.c_str());
   } catch (const std::exception& e) {
     if (kDebugLogging) {
       Logger::get() << mServiceName << ": " << e.what() << LogErrorDevel_(5100) << endm;
     }
-    setDataString(makeFailureString(e.what()), *this);
+    auto reply = makeFailureString(e.what());
+    mDimBuffer = toCharBuffer(reply, true); // keep buffer alive
+    setData(mDimBuffer.data(), mDimBuffer.size());
     alfDebugLog.error("Request failure: %s", e.what());
   }
 }
diff --git a/src/DimServices/DimServices.h b/src/DimServices/DimServices.h
index c179cfb..252438c 100644
--- a/src/DimServices/DimServices.h
+++ b/src/DimServices/DimServices.h
@@ -85,6 +85,7 @@ class StringRpcServer : public DimRpcParallel
 
   Callback mCallback;
   std::string mServiceName;
+  std::vector<char> mDimBuffer;   // owns DIM data
 };
 
 // CLIENT