diff --git a/src/OutputParams.h b/src/OutputParams.h
index f01c5b96b4..8663c1766e 100644
--- a/src/OutputParams.h
+++ b/src/OutputParams.h
@@ -163,11 +163,11 @@ public:
 
 	/** Customized bibtex_command
 	*/
-	mutable std::string bibtex_command;
+	std::string bibtex_command;
 
 	/** Customized index_command
 	*/
-	mutable std::string index_command;
+	std::string index_command;
 
 	/** Line length to use with plaintext or LaTeX export.
 	*/