diff --git a/slsReceiverSoftware/src/DataStreamer.cpp b/slsReceiverSoftware/src/DataStreamer.cpp
index f5db7dfbe..9c96692cc 100755
--- a/slsReceiverSoftware/src/DataStreamer.cpp
+++ b/slsReceiverSoftware/src/DataStreamer.cpp
@@ -227,7 +227,7 @@ int DataStreamer::SendHeader(sls_receiver_header* rheader, uint32_t size, uint32
 
 	return zmqSocket->SendHeaderData(index, dummy, SLS_DETECTOR_JSON_HEADER_VERSION, *dynamicRange, *fileIndex,
 			numDet[0], numDet[1], nx, ny, size,
-			acquisitionIndex, frameIndex, fileNametoStream.c_str(),
+			acquisitionIndex, frameIndex, fileNametoStream,
 			header.frameNumber, header.expLength, header.packetNumber, header.bunchId, header.timestamp,
 			header.modId, header.row, header.column, header.reserved,
 			header.debug, header.roundRNumber,
diff --git a/slsSupportLib/include/ZmqSocket.h b/slsSupportLib/include/ZmqSocket.h
index e4a4a75db..ff1efac43 100755
--- a/slsSupportLib/include/ZmqSocket.h
+++ b/slsSupportLib/include/ZmqSocket.h
@@ -143,7 +143,7 @@ class ZmqSocket {
         int index, bool dummy, uint32_t jsonversion, uint32_t dynamicrange = 0,
         uint64_t fileIndex = 0, uint32_t ndetx = 0, uint32_t ndety = 0,
         uint32_t npixelsx = 0, uint32_t npixelsy = 0, uint32_t imageSize = 0,
-        uint64_t acqIndex = 0, uint64_t fIndex = 0, const char *fname = nullptr,
+        uint64_t acqIndex = 0, uint64_t fIndex = 0, std::string fname = "",
         uint64_t frameNumber = 0, uint32_t expLength = 0,
         uint32_t packetNumber = 0, uint64_t bunchId = 0, uint64_t timestamp = 0,
         uint16_t modId = 0, uint16_t row = 0, uint16_t column = 0,
diff --git a/slsSupportLib/src/ZmqSocket.cpp b/slsSupportLib/src/ZmqSocket.cpp
index 0d606fd6c..ab8c1eb31 100644
--- a/slsSupportLib/src/ZmqSocket.cpp
+++ b/slsSupportLib/src/ZmqSocket.cpp
@@ -309,7 +309,7 @@ int ZmqSocket::SendHeaderData(
     int index, bool dummy, uint32_t jsonversion, uint32_t dynamicrange,
     uint64_t fileIndex, uint32_t ndetx, uint32_t ndety, uint32_t npixelsx,
     uint32_t npixelsy, uint32_t imageSize, uint64_t acqIndex, uint64_t fIndex,
-    const char *fname, uint64_t frameNumber, uint32_t expLength,
+    std::string fname, uint64_t frameNumber, uint32_t expLength,
     uint32_t packetNumber, uint64_t bunchId, uint64_t timestamp, uint16_t modId,
     uint16_t row, uint16_t column, uint16_t reserved, uint32_t debug,
     uint16_t roundRNumber, uint8_t detType, uint8_t version,
@@ -352,7 +352,7 @@ int ZmqSocket::SendHeaderData(
     char buf[MAX_STR_LENGTH] = "";
     sprintf(buf, jsonHeaderFormat, jsonversion, dynamicrange, fileIndex, ndetx,
             ndety, npixelsx, npixelsy, imageSize, acqIndex, fIndex,
-            (fname == NULL) ? "" : fname, dummy ? 0 : 1,
+            fname.c_str(), dummy ? 0 : 1,
 
             frameNumber, expLength, packetNumber, bunchId, timestamp, modId,
             row, column, reserved, debug, roundRNumber, detType, version,