diff --git a/src/BufferParams.h b/src/BufferParams.h
index 66e09f907e..203cac7cd2 100644
--- a/src/BufferParams.h
+++ b/src/BufferParams.h
@@ -385,7 +385,7 @@ public:
 	PDFOptions const & pdfoptions() const;
 
 	enum MathOutput {
-		MathML,
+		MathML = 0,
 		HTML,
 		Images,
 		LaTeX