diff --git a/src/fsfw/cfdp/handler/SourceHandler.cpp b/src/fsfw/cfdp/handler/SourceHandler.cpp
index 141afcef..eba21b7d 100644
--- a/src/fsfw/cfdp/handler/SourceHandler.cpp
+++ b/src/fsfw/cfdp/handler/SourceHandler.cpp
@@ -169,6 +169,10 @@ ReturnValue_t cfdp::SourceHandler::transactionStart(PutRequest& putRequest, Remo
   const char* destNamePtr = putRequest.getDestName().getCString(transactionParams.destNameSize);
   std::strncpy(transactionParams.sourceName.data(), srcNamePtr, transactionParams.sourceNameSize);
   std::strncpy(transactionParams.destName.data(), destNamePtr, transactionParams.destNameSize);
+  // Add 0 termination. The source and dest name size can not be larger than UINT8_MAX, so this
+  // operation is safe.
+  transactionParams.sourceName[transactionParams.sourceNameSize] = '\0';
+  transactionParams.destName[transactionParams.destNameSize] = '\0';
   FilesystemParams params(transactionParams.sourceName.data());
   if (!sourceParams.user.vfs.fileExists(params)) {
     return FILE_DOES_NOT_EXIST;