diff --git a/axelrod/strategies/cooperator.py b/axelrod/strategies/cooperator.py
index 2d10c1f29..4ed0cdf08 100644
--- a/axelrod/strategies/cooperator.py
+++ b/axelrod/strategies/cooperator.py
@@ -1,4 +1,5 @@
 from axelrod import Actions, Player
+from axelrod.actions import Action
 
 C, D = Actions.C, Actions.D
 
@@ -18,7 +19,7 @@ class Cooperator(Player):
     }
 
     @staticmethod
-    def strategy(opponent):
+    def strategy(opponent: Player) -> Action:
         return C
 
 
@@ -37,7 +38,7 @@ class TrickyCooperator(Player):
     }
 
     @staticmethod
-    def strategy(opponent):
+    def strategy(opponent: Player) -> Action:
         """Almost always cooperates, but will try to trick the opponent by defecting.
 
         Defect once in a while in order to get a better payout, when the opponent
diff --git a/axelrod/strategies/cycler.py b/axelrod/strategies/cycler.py
index 730313dfc..3acde1841 100644
--- a/axelrod/strategies/cycler.py
+++ b/axelrod/strategies/cycler.py
@@ -1,4 +1,5 @@
 from axelrod import Actions, Player, init_args
+from axelrod.actions import Action
 
 import copy
 
@@ -20,12 +21,12 @@ class AntiCycler(Player):
         'manipulates_state': False
     }
 
-    def __init__(self):
+    def __init__(self) -> None:
         super().__init__()
         self.cycle_length = 1
         self.cycle_counter = 0
 
-    def strategy(self, opponent):
+    def strategy(self, opponent: Player) -> Action:
         if self.cycle_counter < self.cycle_length:
             self.cycle_counter += 1
             return Actions.C
@@ -55,7 +56,7 @@ class Cycler(Player):
     }
 
     @init_args
-    def __init__(self, cycle="CCD"):
+    def __init__(self, cycle="CCD") -> None:
         """This strategy will repeat the parameter `cycle` endlessly,
         e.g. C C D C C D C C D ...
 
@@ -71,7 +72,7 @@ def __init__(self, cycle="CCD"):
         self.name = "Cycler {}".format(cycle)
         self.classifier['memory_depth'] = len(cycle) - 1
 
-    def strategy(self, opponent):
+    def strategy(self, opponent: Player) -> Action:
         curent_round = len(self.history)
         index = curent_round % len(self.cycle)
         return self.cycle[index]
@@ -84,7 +85,7 @@ class CyclerDC(Cycler):
     classifier['memory_depth'] = 1
 
     @init_args
-    def __init__(self, cycle="DC"):
+    def __init__(self, cycle="DC") -> None:
         super().__init__(cycle=cycle)
 
 
@@ -95,7 +96,7 @@ class CyclerCCD(Cycler):
     classifier['memory_depth'] = 2
 
     @init_args
-    def __init__(self, cycle="CCD"):
+    def __init__(self, cycle="CCD") -> None:
         super().__init__(cycle=cycle)
 
 
@@ -106,7 +107,7 @@ class CyclerDDC(Cycler):
     classifier['memory_depth'] = 2
 
     @init_args
-    def __init__(self, cycle="DDC"):
+    def __init__(self, cycle="DDC") -> None:
         super().__init__(cycle=cycle)
 
 
@@ -117,7 +118,7 @@ class CyclerCCCD(Cycler):
     classifier['memory_depth'] = 3
 
     @init_args
-    def __init__(self, cycle="CCCD"):
+    def __init__(self, cycle="CCCD") -> None:
         super().__init__(cycle=cycle)
 
 
@@ -128,7 +129,7 @@ class CyclerCCCCCD(Cycler):
     classifier['memory_depth'] = 5
 
     @init_args
-    def __init__(self, cycle="CCCCCD"):
+    def __init__(self, cycle="CCCCCD") -> None:
         super().__init__(cycle=cycle)
 
 
@@ -139,5 +140,5 @@ class CyclerCCCDCD(Cycler):
     classifier['memory_depth'] = 5
 
     @init_args
-    def __init__(self, cycle="CCCDCD"):
+    def __init__(self, cycle="CCCDCD") -> None:
         super().__init__(cycle=cycle)
diff --git a/axelrod/strategies/darwin.py b/axelrod/strategies/darwin.py
index 431f9383b..1d76ad815 100644
--- a/axelrod/strategies/darwin.py
+++ b/axelrod/strategies/darwin.py
@@ -1,5 +1,8 @@
 import inspect
 from axelrod import Actions, Player
+from axelrod.actions import Action
+
+from typing import List
 
 C, D = Actions.C, Actions.D
 
@@ -35,14 +38,14 @@ class Darwin(Player):
     genome = [C]
     valid_callers = ["play"]    # What functions may invoke our strategy.
 
-    def __init__(self):
+    def __init__(self) -> None:
         super().__init__()
         self.response = Darwin.genome[0]
 
     def receive_match_attributes(self):
         self.outcomes = self.match_attributes["game"].scores
 
-    def strategy(self, opponent):
+    def strategy(self, opponent: Player) -> Action:
         # Frustrate psychics and ensure that simulated rounds
         # do not influence genome.
         if inspect.stack()[1][3] not in Darwin.valid_callers:
diff --git a/type_tests.sh b/type_tests.sh
index 9cabada32..c06ae1cbd 100755
--- a/type_tests.sh
+++ b/type_tests.sh
@@ -12,4 +12,6 @@ mypy --ignore-missing-imports --follow-imports skip axelrod/strategies/appeaser.
 mypy --ignore-missing-imports --follow-imports skip axelrod/strategies/averagecopier.py
 mypy --ignore-missing-imports --follow-imports skip axelrod/strategies/forgiver.py
 mypy --ignore-missing-imports --follow-imports skip axelrod/strategies/better_and_better.py
-
+mypy --ignore-missing-imports --follow-imports skip axelrod/strategies/darwin.py
+mypy --ignore-missing-imports --follow-imports skip axelrod/strategies/cycler.py
+mypy --ignore-missing-imports --follow-imports skip axelrod/strategies/cooperator.py