diff --git a/contrib/ethereum/libethash/ethash/progpow.hpp b/contrib/ethereum/libethash/ethash/progpow.hpp
index 8add7d4d..f7768778 100644
--- a/contrib/ethereum/libethash/ethash/progpow.hpp
+++ b/contrib/ethereum/libethash/ethash/progpow.hpp
@@ -14,11 +14,11 @@ namespace progpow
 {
 using namespace ethash;  // Include ethash namespace.
 
-constexpr int period_length = 50;
+constexpr int period_length = 10;
 constexpr uint32_t num_regs = 32;
 constexpr size_t num_lanes = 16;
-constexpr int num_cache_accesses = 12;
-constexpr int num_math_operations = 20;
+constexpr int num_cache_accesses = 11;
+constexpr int num_math_operations = 18;
 constexpr size_t l1_cache_size = 16 * 1024;
 constexpr size_t l1_cache_num_items = l1_cache_size / sizeof(uint32_t);