diff --git a/src/content_cao.cpp b/src/content_cao.cpp
index 9344b3370..1955559b5 100644
--- a/src/content_cao.cpp
+++ b/src/content_cao.cpp
@@ -990,7 +990,7 @@ void GenericCAO::updateTexturePos()
 	}
 }
 
-void GenericCAO::updateTextures(const std::string &mod)
+void GenericCAO::updateTextures(std::string mod)
 {
 	ITextureSource *tsrc = m_client->tsrc();
 
diff --git a/src/content_cao.h b/src/content_cao.h
index a93df664a..d2c8d772e 100644
--- a/src/content_cao.h
+++ b/src/content_cao.h
@@ -198,8 +198,8 @@ public:
 	void updateTexturePos();
 
 	// std::string copy is mandatory as mod can be a class member and there is a swap
-	// on those class members
-	void updateTextures(const std::string &mod);
+	// on those class members... do NOT pass by reference
+	void updateTextures(std::string mod);
 
 	void updateAnimation();