diff --git a/lib/tools/currency-params/src/constants.rs b/lib/tools/currency-params/src/constants.rs
index 79f3899d9b3c409fe6bc6a7933e0465c354ba28e..fb1ffea735806796a42c99f07ab3f934b4b8838b 100644
--- a/lib/tools/currency-params/src/constants.rs
+++ b/lib/tools/currency-params/src/constants.rs
@@ -27,4 +27,4 @@ pub static DEFAULT_MS_PERIOD: &'static u64 = &5_259_600;
 /// Default value for tx_window parameter
 pub static DEFAULT_TX_WINDOW: &'static u64 = &604_800;
 /// Default maximum roolback length
-pub static DEFAULT_FORK_WINDOW_SIZE: &'static usize = &200;
+pub static DEFAULT_FORK_WINDOW_SIZE: &'static usize = &100;
diff --git a/lib/tools/currency-params/src/lib.rs b/lib/tools/currency-params/src/lib.rs
index b8a3dde5e0ff51af5f0459f9ebd08104827b36b2..258fb7f06c8699622cd7f62ab84fad3fd2099912 100644
--- a/lib/tools/currency-params/src/lib.rs
+++ b/lib/tools/currency-params/src/lib.rs
@@ -132,8 +132,8 @@ impl From<(&CurrencyName, BlockV10Parameters)> for CurrencyParameters {
         };
         let fork_window_size = match currency_name.0.as_str() {
             DEFAULT_CURRENCY => *DEFAULT_FORK_WINDOW_SIZE,
-            "g1" => 200,
-            "g1-test" => 200,
+            "g1" => 100,
+            "g1-test" => 100,
             _ => *DEFAULT_FORK_WINDOW_SIZE,
         };
         CurrencyParameters {