diff --git a/tests/parser/features/decorators/test_nonreentrant.py b/tests/parser/features/decorators/test_nonreentrant.py
index a844e13b32..fa0cbad1e8 100644
--- a/tests/parser/features/decorators/test_nonreentrant.py
+++ b/tests/parser/features/decorators/test_nonreentrant.py
@@ -30,11 +30,14 @@ def set_callback(c: address):
 
 @public
 @nonreentrant('protect_special_value')
-def protected_function(val: string[100], do_callback: bool):
+def protected_function(val: string[100], do_callback: bool) -> uint256:
     self.special_value = val
 
     if do_callback:
         self.callback.updated_protected()
+        return 1
+    else:
+        return 2
 
 @public
 def unprotected_function(val: string[100], do_callback: bool):
diff --git a/vyper/parser/context.py b/vyper/parser/context.py
index ea64a83d76..81bcbd27e2 100644
--- a/vyper/parser/context.py
+++ b/vyper/parser/context.py
@@ -33,7 +33,8 @@ def __init__(self,
                  is_private=False,
                  is_payable=False,
                  origcode='',
-                 method_id=''):
+                 method_id='',
+                 sig=None):
         # In-memory variables, in the form (name, memory location, type)
         self.vars = vars or {}
         # Memory alloctor, keeps track of currently allocated memory.
@@ -79,6 +80,8 @@ def __init__(self,
         self.method_id = method_id
         # store global context
         self.global_ctx = global_ctx
+        # full function signature
+        self.sig = sig
 
     def is_constant(self):
         return self.constancy is Constancy.Constant or \
diff --git a/vyper/parser/function_definitions/parse_function.py b/vyper/parser/function_definitions/parse_function.py
index 00888c074a..5b80157de9 100644
--- a/vyper/parser/function_definitions/parse_function.py
+++ b/vyper/parser/function_definitions/parse_function.py
@@ -62,7 +62,8 @@ def parse_function(code, sigs, origcode, global_ctx, _vars=None):
         is_payable=sig.payable,
         origcode=origcode,
         is_private=sig.private,
-        method_id=sig.method_id
+        method_id=sig.method_id,
+        sig=sig
     )
 
     if sig.private:
diff --git a/vyper/parser/parser_utils.py b/vyper/parser/parser_utils.py
index 5b8f805a31..b5e7199128 100644
--- a/vyper/parser/parser_utils.py
+++ b/vyper/parser/parser_utils.py
@@ -906,6 +906,10 @@ def zero_pad(bytez_placeholder, maxlen, context):
 
 # Generate return code for stmt
 def make_return_stmt(stmt, context, begin_pos, _size, loop_memory_position=None):
+    from vyper.parser.function_definitions.utils import (
+        get_nonreentrant_lock
+    )
+    _, nonreentrant_post = get_nonreentrant_lock(context.sig, context.global_ctx)
     if context.is_private:
         if loop_memory_position is None:
             loop_memory_position = context.new_placeholder(typ=BaseType('uint256'))
@@ -922,7 +926,8 @@ def make_return_stmt(stmt, context, begin_pos, _size, loop_memory_position=None)
             mloads = [
                 ['mload', pos] for pos in range(begin_pos, _size, 32)
             ]
-            return ['seq_unchecked'] + mloads + [['jump', ['mload', context.callback_ptr]]]
+            return ['seq_unchecked'] + mloads + nonreentrant_post + \
+                [['jump', ['mload', context.callback_ptr]]]
         else:
             mloads = [
                 'seq_unchecked',
@@ -945,9 +950,10 @@ def make_return_stmt(stmt, context, begin_pos, _size, loop_memory_position=None)
                 ['goto', start_label],
                 ['label', exit_label]
             ]
-            return ['seq_unchecked'] + [mloads] + [['jump', ['mload', context.callback_ptr]]]
+            return ['seq_unchecked'] + [mloads] + nonreentrant_post + \
+                [['jump', ['mload', context.callback_ptr]]]
     else:
-        return ['return', begin_pos, _size]
+        return ['seq_unchecked'] + nonreentrant_post + [['return', begin_pos, _size]]
 
 
 # Generate code for returning a tuple or struct.
diff --git a/vyper/parser/self_call.py b/vyper/parser/self_call.py
index 072ef9885d..237a5183b0 100644
--- a/vyper/parser/self_call.py
+++ b/vyper/parser/self_call.py
@@ -130,7 +130,7 @@ def call_self_private(stmt_expr, context, sig):
         static_arg_size = 32 * sum(
                 [get_static_size_of_type(arg.typ)
                     for arg in expr_args])
-        static_pos = arg_pos + static_arg_size
+        static_pos = int(arg_pos + static_arg_size)
         needs_dyn_section = any(
                 [has_dynamic_data(arg.typ)
                     for arg in expr_args])