diff --git a/lldb/source/Core/FormatEntity.cpp b/lldb/source/Core/FormatEntity.cpp
--- a/lldb/source/Core/FormatEntity.cpp
+++ b/lldb/source/Core/FormatEntity.cpp
@@ -2347,7 +2347,7 @@
 }
 
 size_t FormatEntity::AutoComplete(CompletionRequest &request) {
-  llvm::StringRef str = request.GetCursorArgumentPrefix().str();
+  llvm::StringRef str = request.GetCursorArgumentPrefix();
 
   request.SetWordComplete(false);