diff --git a/diffcore.h b/diffcore.h
index 12cd81659..91d6c631e 100644
--- a/diffcore.h
+++ b/diffcore.h
@@ -18,7 +18,7 @@
 #define MAX_SCORE 60000.0
 #define DEFAULT_RENAME_SCORE 30000 /* rename/copy similarity minimum (50%) */
 #define DEFAULT_BREAK_SCORE  30000 /* minimum for break to happen (50%)*/
-#define DEFAULT_MERGE_SCORE  48000 /* maximum for break-merge to happen (80%)*/
+#define DEFAULT_MERGE_SCORE  45000 /* maximum for break-merge to happen (75%)*/
 
 #define MINIMUM_BREAK_SIZE     400 /* do not break a file smaller than this */