diff --git a/mpn/x86_64/k8/gmp-mparam.h b/mpn/x86_64/k8/gmp-mparam.h
index 0d622e18..83636dc7 100644
--- a/mpn/x86_64/k8/gmp-mparam.h
+++ b/mpn/x86_64/k8/gmp-mparam.h
@@ -14,7 +14,8 @@
 #define POWM_THRESHOLD                  414
 
 #define GCD_ACCEL_THRESHOLD              93
-
+#define GCD_THRESHOLD                   442
+#define GCDEXT_THRESHOLD                996
 #define JACOBI_BASE_METHOD                1
 
 #define DIVREM_1_NORM_THRESHOLD       MP_SIZE_T_MAX  /* never */