diff --git a/rainbowadn/wrisbt/wrisbtchainprotocol.py b/rainbowadn/wrisbt/wrisbtchainprotocol.py
index 5fe159e..5ad5689 100644
--- a/rainbowadn/wrisbt/wrisbtchainprotocol.py
+++ b/rainbowadn/wrisbt/wrisbtchainprotocol.py
@@ -28,7 +28,7 @@ class WrisbtChainProtocol(
     ):
         assert isinstance(total_factory, RainbowFactory)
         assert isinstance(keymin, int)
-        assert keymin >= 2
+        assert keymin > 0
         self.keymin = keymin
         super().__init__(
             WrisbtProtocol(keymin),
diff --git a/rainbowadn/wrisbt/wrisbtindex.py b/rainbowadn/wrisbt/wrisbtindex.py
index 620a64a..c0e81ef 100644
--- a/rainbowadn/wrisbt/wrisbtindex.py
+++ b/rainbowadn/wrisbt/wrisbtindex.py
@@ -24,7 +24,7 @@ class WrisbtIndex(RecursiveMentionable):
         assert isinstance(keymin, int)
         self.total = total
         self.delta = delta
-        assert keymin >= 2
+        assert keymin > 0
         self.keymin = keymin
 
     def points(self) -> Iterable[HashPoint]:
@@ -46,7 +46,7 @@ class WrisbtIndex(RecursiveMentionable):
 class WrisbtIndexFactory(RainbowFactory[WrisbtIndex]):
     def __init__(self, keymin: int):
         assert isinstance(keymin, int)
-        assert keymin >= 2
+        assert keymin > 0
         self.keymin = keymin
         self.root_factory: RainbowFactory[WrisbtRoot] = WrisbtRootFactory(
             WrisbtParametres(keymin, HashPoint.HASH_LENGTH)
diff --git a/rainbowadn/wrisbt/wrisbtprotocol.py b/rainbowadn/wrisbt/wrisbtprotocol.py
index 10e5c95..c999123 100644
--- a/rainbowadn/wrisbt/wrisbtprotocol.py
+++ b/rainbowadn/wrisbt/wrisbtprotocol.py
@@ -14,7 +14,7 @@ TargetType = TypeVar('TargetType')
 class WrisbtProtocol(MetaReductionStateProtocol[TargetType, WrisbtIndex]):
     def __init__(self, keymin: int):
         assert isinstance(keymin, int)
-        assert keymin >= 2
+        assert keymin > 0
         self.keymin = keymin
 
     def _initial_state(self) -> HashPoint[WrisbtIndex]: