diff --git a/src/intra.h b/src/intra.h
index 846d77b2..bc125e83 100644
--- a/src/intra.h
+++ b/src/intra.h
@@ -43,9 +43,12 @@
 #include "kvazaar.h"
 
 
+// Maximum additional reference lines for MRL intra
+#define MAX_REF_LINE_IDX 3
+
 typedef struct {
-  kvz_pixel left[2 * 128 + 3];
-  kvz_pixel top[2 * 128 + 3];
+  kvz_pixel left[2 * 128 + 3 + 33 * MAX_REF_LINE_IDX];
+  kvz_pixel top[2 * 128 + 3 + 33 * MAX_REF_LINE_IDX];
 } kvz_intra_ref;
 typedef struct
 {