diff --git a/renderdoc/driver/shaders/dxbc/dxbc_common.h b/renderdoc/driver/shaders/dxbc/dxbc_common.h
index 6a581ba79..417b7aa4a 100644
--- a/renderdoc/driver/shaders/dxbc/dxbc_common.h
+++ b/renderdoc/driver/shaders/dxbc/dxbc_common.h
@@ -414,6 +414,6 @@ public:
                          rdcarray<SourceVariableMapping> &locals) const = 0;
 };
 
-rdcstr BasicDemangle(rdcstr possiblyMangledName);
+rdcstr BasicDemangle(const rdcstr &possiblyMangledName);
 
 };
diff --git a/renderdoc/driver/shaders/dxbc/dxbc_container.cpp b/renderdoc/driver/shaders/dxbc/dxbc_container.cpp
index e39811b48..53b325a7e 100644
--- a/renderdoc/driver/shaders/dxbc/dxbc_container.cpp
+++ b/renderdoc/driver/shaders/dxbc/dxbc_container.cpp
@@ -42,7 +42,7 @@ RDOC_EXTERN_CONFIG(rdcarray<rdcstr>, DXBC_Debug_SearchDirPaths);
 
 namespace DXBC
 {
-rdcstr BasicDemangle(rdcstr possiblyMangledName)
+rdcstr BasicDemangle(const rdcstr &possiblyMangledName)
 {
   if(possiblyMangledName.size() > 2 && possiblyMangledName[0] == '\x1' &&
      possiblyMangledName[1] == '?')