diff --git a/mythril/laser/ethereum/instructions.py b/mythril/laser/ethereum/instructions.py
index ac6033da..32def7e2 100644
--- a/mythril/laser/ethereum/instructions.py
+++ b/mythril/laser/ethereum/instructions.py
@@ -517,9 +517,44 @@ class Instruction:
 
     @instruction
     def codecopy_(self, global_state):
-        # FIXME: not implemented
-        state = global_state.mstate
-        start, s1, size = state.stack.pop(), state.stack.pop(), state.stack.pop()
+        memory_offset, code_offset, size = global_state.mstate.stack.pop(), global_state.mstate.stack.pop(), global_state.mstate.stack.pop()
+
+        try:
+            concrete_memory_offset = helper.get_concrete_int(memory_offset)
+        except AttributeError:
+            logging.debug("Unsupported symbolic memory offset in CODECOPY")
+            return [global_state]
+
+        try:
+            concrete_size = helper.get_concrete_int(size)
+            global_state.mstate.mem_extend(concrete_memory_offset, concrete_size)
+        except:
+            # except both attribute error and Exception
+            global_state.mstate.mem_extend(concrete_memory_offset, 1)
+            global_state.mstate.memory[concrete_memory_offset] = \
+                BitVec("code({})".format(global_state.environment.active_account.contract_name), 256)
+            return [global_state]
+
+        try:
+            concrete_code_offset = helper.get_concrete_int(code_offset)
+        except AttributeError:
+            logging.debug("Unsupported symbolic code offset in CODECOPY")
+            global_state.mstate.mem_extend(concrete_memory_offset, concrete_size)
+            for i in range(concrete_size):
+                global_state.mstate.memory[concrete_memory_offset + i] = \
+                    BitVec("code({})".format(global_state.environment.active_account.contract_name), 256)
+            return [global_state]
+
+        bytecode = global_state.environment.active_account.code.bytecode
+
+        for i in range(concrete_size):
+            try:
+                global_state.mstate.memory[concrete_memory_offset + i] =\
+                    int(bytecode[2*(concrete_code_offset + i): 2*(concrete_code_offset + i + 1)], 16)
+            except IndexError:
+                global_state.mstate.memory[concrete_memory_offset + i] = \
+                    BitVec("code({})".format(global_state.environment.active_account.contract_name), 256)
+
         return [global_state]
 
     @instruction
diff --git a/mythril/laser/ethereum/state.py b/mythril/laser/ethereum/state.py
index 751c1c6e..c5f3a917 100644
--- a/mythril/laser/ethereum/state.py
+++ b/mythril/laser/ethereum/state.py
@@ -68,6 +68,7 @@ class Environment:
         calldata_type=CalldataType.SYMBOLIC,
     ):
         # Metadata
+
         self.active_account = active_account
         self.active_function_name = ""
 
diff --git a/tests/instructions/__init__.py b/tests/instructions/__init__.py
new file mode 100644
index 00000000..e69de29b
diff --git a/tests/instructions/codecopy_test.py b/tests/instructions/codecopy_test.py
new file mode 100644
index 00000000..53ae049d
--- /dev/null
+++ b/tests/instructions/codecopy_test.py
@@ -0,0 +1,20 @@
+from mythril.disassembler.disassembly import Disassembly
+from mythril.laser.ethereum.state import MachineState, GlobalState, Environment, Account
+from mythril.laser.ethereum.instructions import Instruction
+
+
+def test_codecopy_concrete():
+    # Arrange
+    active_account = Account("0x0", code= Disassembly("60606040"))
+    environment = Environment(active_account, None, None, None, None, None)
+    og_state = GlobalState(None, environment, None, MachineState(gas=10000000))
+
+    og_state.mstate.stack = [2, 2, 2]
+    instruction = Instruction("codecopy", dynamic_loader=None)
+
+    # Act
+    new_state = instruction.evaluate(og_state)[0]
+
+    # Assert
+    assert new_state.mstate.memory[2] == 96
+    assert new_state.mstate.memory[3] == 64
diff --git a/tests/report_test.py b/tests/report_test.py
index 7f1da181..a5c41f21 100644
--- a/tests/report_test.py
+++ b/tests/report_test.py
@@ -38,7 +38,7 @@ def _generate_report(input_file):
 def reports():
     """ Fixture that analyses all reports"""
     pool = Pool(cpu_count())
-    input_files = [f for f in TESTDATA_INPUTS.iterdir()]
+    input_files = sorted([f for f in TESTDATA_INPUTS.iterdir()])
     results = pool.map(_generate_report, input_files)
 
     return results