diff --git a/tests/parser/features/iteration/test_for_in_list.py b/tests/parser/features/iteration/test_for_in_list.py
index bfd960a787..d614b28f60 100644
--- a/tests/parser/features/iteration/test_for_in_list.py
+++ b/tests/parser/features/iteration/test_for_in_list.py
@@ -20,7 +20,7 @@
 @external
 def data() -> int128:
     s: int128[5] = [1, 2, 3, 4, 5]
-    for i in s:
+    for i: int128 in s:
         if i >= 3:
             return i
     return -1""",
@@ -32,7 +32,7 @@ def data() -> int128:
 @external
 def data() -> int128:
     s: DynArray[int128, 10] = [1, 2, 3, 4, 5]
-    for i in s:
+    for i: int128 in s:
         if i >= 3:
             return i
     return -1""",
@@ -52,8 +52,8 @@ def data() -> int128:
         [S({x:3, y:4}), S({x:5, y:6}), S({x:7, y:8}), S({x:9, y:10})]
         ]
     ret: int128 = 0
-    for ss in sss:
-        for s in ss:
+    for ss: DynArray[S, 10] in sss:
+        for s: S in ss:
             ret += s.x + s.y
     return ret""",
         sum(range(1, 11)),
@@ -63,7 +63,7 @@ def data() -> int128:
         """
 @external
 def data() -> int128:
-    for i in [3, 5, 7, 9]:
+    for i: int128 in [3, 5, 7, 9]:
         if i > 5:
             return i
     return -1""",
@@ -75,7 +75,7 @@ def data() -> int128:
 @external
 def data() -> String[33]:
     xs: DynArray[String[33], 3] = ["hello", ",", "world"]
-    for x in xs:
+    for x: String[33] in xs:
         if x == ",":
             return x
     return ""
@@ -87,7 +87,7 @@ def data() -> String[33]:
         """
 @external
 def data() -> String[33]:
-    for x in ["hello", ",", "world"]:
+    for x: String[33] in ["hello", ",", "world"]:
         if x == ",":
             return x
     return ""
@@ -99,7 +99,7 @@ def data() -> String[33]:
         """
 @external
 def data() -> DynArray[String[33], 2]:
-    for x in [["hello", "world"], ["goodbye", "world!"]]:
+    for x: DynArray[String[33], 2] in [["hello", "world"], ["goodbye", "world!"]]:
         if x[1] == "world":
             return x
     return []
@@ -113,8 +113,8 @@ def data() -> DynArray[String[33], 2]:
 def data() -> int128:
     ret: int128 = 0
     xss: int128[3][3] = [[1,2,3],[4,5,6],[7,8,9]]
-    for xs in xss:
-        for x in xs:
+    for xs: int128[3] in xss:
+        for x: int128 in xs:
             ret += x
     return ret""",
         sum(range(1, 10)),
@@ -129,8 +129,8 @@ def data() -> int128:
 @external
 def data() -> int128:
     ret: int128 = 0
-    for ss in [[S({x:1, y:2})]]:
-        for s in ss:
+    for ss: S[1] in [[S({x:1, y:2})]]:
+        for s: S in ss:
             ret += s.x + s.y
     return ret""",
         1 + 2,
@@ -146,7 +146,7 @@ def data() -> address:
         0xDCEceAF3fc5C0a63d195d69b1A90011B7B19650D
     ]
     count: int128 = 0
-    for i in addresses:
+    for i: address in addresses:
         count += 1
         if count == 2:
             return i
@@ -173,7 +173,7 @@ def set():
 
 @external
 def data() -> int128:
-    for i in self.x:
+    for i: int128 in self.x:
         if i > 5:
             return i
     return -1
@@ -197,7 +197,7 @@ def set(xs: DynArray[int128, 4]):
 @external
 def data() -> int128:
     t: int128 = 0
-    for i in self.x:
+    for i: int128 in self.x:
         t += i
     return t
     """
@@ -226,7 +226,7 @@ def ret(i: int128) -> address:
 @external
 def iterate_return_second() -> address:
     count: int128 = 0
-    for i in self.addresses:
+    for i: address in self.addresses:
         count += 1
         if count == 2:
             return i
@@ -257,7 +257,7 @@ def ret(i: int128) -> decimal:
 @external
 def i_return(break_count: int128) -> decimal:
     count: int128 = 0
-    for i in self.readings:
+    for i: decimal in self.readings:
         if count == break_count:
             return i
         count += 1
@@ -283,7 +283,7 @@ def func(amounts: uint256[3]) -> uint256:
     total: uint256 = as_wei_value(0, "wei")
 
     # calculate total
-    for amount in amounts:
+    for amount: uint256 in amounts:
         total += amount
 
     return total
@@ -302,7 +302,7 @@ def func(amounts: DynArray[uint256, 3]) -> uint256:
     total: uint256 = 0
 
     # calculate total
-    for amount in amounts:
+    for amount: uint256 in amounts:
         total += amount
 
     return total
@@ -320,42 +320,42 @@ def func(amounts: DynArray[uint256, 3]) -> uint256:
 @external
 def foo(x: int128):
     p: int128 = 0
-    for i in range(3):
+    for i: int128 in range(3):
         p += i
-    for i in range(4):
+    for i: int128 in range(4):
         p += i
     """,
     """
 @external
 def foo(x: int128):
     p: int128 = 0
-    for i in range(3):
+    for i: int128 in range(3):
         p += i
-    for i in [1, 2, 3, 4]:
+    for i: int128 in [1, 2, 3, 4]:
         p += i
     """,
     """
 @external
 def foo(x: int128):
     p: int128 = 0
-    for i in [1, 2, 3, 4]:
+    for i: int128 in [1, 2, 3, 4]:
         p += i
-    for i in [1, 2, 3, 4]:
+    for i: int128 in [1, 2, 3, 4]:
         p += i
     """,
     """
 @external
 def foo():
-    for i in range(10):
+    for i: uint256 in range(10):
         pass
-    for i in range(20):
+    for i: uint256 in range(20):
         pass
     """,
     # using index variable after loop
     """
 @external
 def foo():
-    for i in range(10):
+    for i: int128 in range(10):
         pass
     i: int128 = 100  # create new variable i
     i = 200  # look up the variable i and check whether it is in forvars
@@ -377,7 +377,7 @@ def test_good_code(code, get_contract):
 @external
 def a() -> uint256:
     x: uint256 = 0
-    for i in range(TREE_FIDDY):
+    for i: int128 in range(TREE_FIDDY):
         x += 1
     return x""",
         350,
@@ -389,7 +389,7 @@ def a() -> uint256:
 @external
 def a() -> uint256:
     x: uint256 = 0
-    for i in range(1, 1 + ONE_HUNDRED):
+    for i: uint256 in range(1, 1 + ONE_HUNDRED):
         x += 1
     return x""",
         100,
@@ -400,9 +400,9 @@ def a() -> uint256:
 END: constant(int128)  = 199
 
 @external
-def a() -> uint256:
-    x: uint256 = 0
-    for i in range(START, END):
+def a() -> int128:
+    x: int128 = 0
+    for i: int128 in range(START, END):
         x += 1
     return x""",
         99,
@@ -412,7 +412,7 @@ def a() -> uint256:
 @external
 def a() -> int128:
     x: int128 = 0
-    for i in range(-5, -1):
+    for i: int128 in range(-5, -1):
         x += i
     return x""",
         -14,
@@ -435,7 +435,7 @@ def test_range_constant(get_contract, code, result):
 def data() -> int128:
     s: int128[6] = [1, 2, 3, 4, 5, 6]
     count: int128 = 0
-    for i in s:
+    for i: int128 in s:
         s[count] = 1  # this should not be allowed.
         if i >= 3:
             return i
@@ -450,7 +450,7 @@ def data() -> int128:
 def foo():
     s: int128[6] = [1, 2, 3, 4, 5, 6]
     count: int128 = 0
-    for i in s:
+    for i: int128 in s:
         s[count] += 1
     """,
         ImmutableViolation,
@@ -467,7 +467,7 @@ def set():
 @external
 def data() -> int128:
     count: int128 = 0
-    for i in self.s:
+    for i: int128 in self.s:
         self.s[count] = 1  # this should not be allowed.
         if i >= 3:
             return i
@@ -492,7 +492,7 @@ def doStuff(i: uint256) -> uint256:
 @internal
 def _helper():
     i: uint256 = 0
-    for item in self.my_array2.foo:
+    for item: uint256 in self.my_array2.foo:
         self.doStuff(i)
         i += 1
     """,
@@ -518,7 +518,7 @@ def doStuff(i: uint256) -> uint256:
 @internal
 def _helper():
     i: uint256 = 0
-    for item in self.my_array2.bar.foo:
+    for item: uint256 in self.my_array2.bar.foo:
         self.doStuff(i)
         i += 1
     """,
@@ -544,7 +544,7 @@ def doStuff():
 @internal
 def _helper():
     i: uint256 = 0
-    for item in self.my_array2.foo:
+    for item: uint256 in self.my_array2.foo:
         self.doStuff()
         i += 1
     """,
@@ -555,8 +555,8 @@ def _helper():
         """
 @external
 def foo(x: int128):
-    for i in range(4):
-        for i in range(5):
+    for i: int128 in range(4):
+        for i: int128 in range(5):
             pass
     """,
         NamespaceCollision,
@@ -565,8 +565,8 @@ def foo(x: int128):
         """
 @external
 def foo(x: int128):
-    for i in [1,2]:
-        for i in [1,2]:
+    for i: int128 in [1,2]:
+        for i: int128 in [1,2]:
             pass
      """,
         NamespaceCollision,
@@ -576,7 +576,7 @@ def foo(x: int128):
         """
 @external
 def foo(x: int128):
-    for i in [1,2]:
+    for i: int128 in [1,2]:
         i = 2
     """,
         ImmutableViolation,
@@ -587,7 +587,7 @@ def foo(x: int128):
 @external
 def foo():
     xs: DynArray[uint256, 5] = [1,2,3]
-    for x in xs:
+    for x: uint256 in xs:
         xs.pop()
     """,
         ImmutableViolation,
@@ -598,7 +598,7 @@ def foo():
 @external
 def foo():
     xs: DynArray[uint256, 5] = [1,2,3]
-    for x in xs:
+    for x: uint256 in xs:
         xs.append(x)
     """,
         ImmutableViolation,
@@ -609,7 +609,7 @@ def foo():
 @external
 def foo():
     xs: DynArray[DynArray[uint256, 5], 5] = [[1,2,3]]
-    for x in xs:
+    for x: DynArray[uint256, 5] in xs:
         x.pop()
     """,
         ImmutableViolation,
@@ -628,7 +628,7 @@ def b():
 
 @external
 def foo():
-    for x in self.array:
+    for x: uint256 in self.array:
         self.a()
     """,
         ImmutableViolation,
@@ -637,7 +637,7 @@ def foo():
         """
 @external
 def foo(x: int128):
-    for i in [1,2]:
+    for i: int128 in [1,2]:
         i += 2
     """,
         ImmutableViolation,
@@ -647,7 +647,7 @@ def foo(x: int128):
         """
 @external
 def foo():
-    for i in range(-3):
+    for i: int128 in range(-3):
         pass
     """,
         StructureException,
@@ -655,13 +655,13 @@ def foo():
     """
 @external
 def foo():
-    for i in range(0):
+    for i: int128 in range(0):
         pass
     """,
     """
 @external
 def foo():
-    for i in []:
+    for i: int128 in []:
         pass
     """,
     """
@@ -669,14 +669,14 @@ def foo():
 
 @external
 def foo():
-    for i in FOO:
+    for i: uint256 in FOO:
         pass
     """,
     (
         """
 @external
 def foo():
-    for i in range(5,3):
+    for i: int128 in range(5,3):
         pass
     """,
         StructureException,
@@ -685,7 +685,7 @@ def foo():
         """
 @external
 def foo():
-    for i in range(5,3,-1):
+    for i: int128 in range(5,3,-1):
         pass
     """,
         ArgumentException,
@@ -695,7 +695,7 @@ def foo():
 @external
 def foo():
     a: uint256 = 2
-    for i in range(a):
+    for i: uint256 in range(a):
         pass
     """,
         StateAccessViolation,
@@ -704,7 +704,7 @@ def foo():
 @external
 def foo():
     a: int128 = 6
-    for i in range(a,a-3):
+    for i: int128 in range(a,a-3):
         pass
     """,
     # invalid argument length
@@ -712,7 +712,7 @@ def foo():
         """
 @external
 def foo():
-    for i in range():
+    for i: uint256 in range():
         pass
     """,
         ArgumentException,
@@ -721,7 +721,7 @@ def foo():
         """
 @external
 def foo():
-    for i in range(0,1,2):
+    for i: uint256 in range(0,1,2):
         pass
     """,
         ArgumentException,
@@ -731,7 +731,7 @@ def foo():
         """
 @external
 def foo():
-    for i in b"asdf":
+    for i: Bytes[1] in b"asdf":
         pass
     """,
         InvalidType,
@@ -740,7 +740,7 @@ def foo():
         """
 @external
 def foo():
-    for i in 31337:
+    for i: uint256 in 31337:
         pass
     """,
         InvalidType,
@@ -749,16 +749,7 @@ def foo():
         """
 @external
 def foo():
-    for i in bar():
-        pass
-    """,
-        IteratorException,
-    ),
-    (
-        """
-@external
-def foo():
-    for i in self.bar():
+    for i: uint256 in bar():
         pass
     """,
         IteratorException,
@@ -768,11 +759,11 @@ def foo():
 @external
 def test_for() -> int128:
     a: int128 = 0
-    for i in range(max_value(int128), max_value(int128)+2):
+    for i: int128 in range(max_value(int128), max_value(int128)+2):
         a = i
     return a
     """,
-        TypeMismatch,
+        InvalidType,
     ),
     (
         """
@@ -780,7 +771,7 @@ def test_for() -> int128:
 def test_for() -> int128:
     a: int128 = 0
     b: uint256 = 0
-    for i in range(5):
+    for i: int128 in range(5):
         a = i
         b = i
     return a
diff --git a/tests/parser/features/iteration/test_for_range.py b/tests/parser/features/iteration/test_for_range.py
index 395dd28231..104218b357 100644
--- a/tests/parser/features/iteration/test_for_range.py
+++ b/tests/parser/features/iteration/test_for_range.py
@@ -6,7 +6,7 @@ def test_basic_repeater(get_contract_with_gas_estimation):
 @external
 def repeat(z: int128) -> int128:
     x: int128 = 0
-    for i in range(6):
+    for i: int128 in range(6):
         x = x + z
     return(x)
     """
@@ -19,7 +19,7 @@ def test_range_bound(get_contract, assert_tx_failed):
 @external
 def repeat(n: uint256) -> uint256:
     x: uint256 = 0
-    for i in range(n, bound=6):
+    for i: uint256 in range(n, bound=6):
         x += i
     return x
     """
@@ -37,11 +37,11 @@ def test_digit_reverser(get_contract_with_gas_estimation):
 def reverse_digits(x: int128) -> int128:
     dig: int128[6] = [0, 0, 0, 0, 0, 0]
     z: int128 = x
-    for i in range(6):
+    for i: int128 in range(6):
         dig[i] = z % 10
         z = z / 10
     o: int128 = 0
-    for i in range(6):
+    for i: int128 in range(6):
         o = o * 10 + dig[i]
     return o
 
@@ -56,9 +56,9 @@ def test_more_complex_repeater(get_contract_with_gas_estimation):
 @external
 def repeat() -> int128:
     out: int128 = 0
-    for i in range(6):
+    for i: int128 in range(6):
         out = out * 10
-        for j in range(4):
+        for j: int128 in range(4):
             out = out + j
     return(out)
     """
@@ -73,7 +73,7 @@ def test_offset_repeater(get_contract_with_gas_estimation, typ):
 @external
 def sum() -> {typ}:
     out: {typ} = 0
-    for i in range(80, 121):
+    for i: {typ} in range(80, 121):
         out = out + i
     return out
     """
@@ -88,7 +88,7 @@ def test_offset_repeater_2(get_contract_with_gas_estimation, typ):
 @external
 def sum(frm: {typ}, to: {typ}) -> {typ}:
     out: {typ} = 0
-    for i in range(frm, frm + 101):
+    for i: {typ} in range(frm, frm + 101):
         if i == to:
             break
         out = out + i
@@ -108,7 +108,7 @@ def _bar() -> bool:
 
 @external
 def foo() -> bool:
-    for i in range(3):
+    for i: int128 in range(3):
         self._bar()
     return True
     """
@@ -122,8 +122,8 @@ def test_return_inside_repeater(get_contract, typ):
     code = f"""
 @internal
 def _final(a: {typ}) -> {typ}:
-    for i in range(10):
-        for j in range(10):
+    for i: {typ} in range(10):
+        for j: {typ} in range(10):
             if j > 5:
                 if i > a:
                     return i
@@ -153,7 +153,7 @@ def test_for_range_edge(get_contract, typ):
 def test():
     found: bool = False
     x: {typ} = max_value({typ})
-    for i in range(x, x + 1):
+    for i: {typ} in range(x, x + 1):
         if i == max_value({typ}):
             found = True
 
@@ -161,7 +161,7 @@ def test():
 
     found = False
     x = max_value({typ}) - 1
-    for i in range(x, x + 2):
+    for i: {typ} in range(x, x + 2):
         if i == max_value({typ}):
             found = True
 
@@ -177,7 +177,7 @@ def test_for_range_oob_check(get_contract, assert_tx_failed, typ):
 @external
 def test():
     x: {typ} = max_value({typ})
-    for i in range(x, x+2):
+    for i: {typ} in range(x, x+2):
         pass
     """
     c = get_contract(code)
@@ -189,8 +189,8 @@ def test_return_inside_nested_repeater(get_contract, typ):
     code = f"""
 @internal
 def _final(a: {typ}) -> {typ}:
-    for i in range(10):
-        for x in range(10):
+    for i: {typ} in range(10):
+        for x: {typ} in range(10):
             if i + x > a:
                 return i + x
     return 31337
@@ -218,8 +218,8 @@ def test_return_void_nested_repeater(get_contract, typ, val):
 result: {typ}
 @internal
 def _final(a: {typ}):
-    for i in range(10):
-        for x in range(10):
+    for i: {typ} in range(10):
+        for x: {typ} in range(10):
             if i + x > a:
                 self.result = i + x
                 return
@@ -247,8 +247,8 @@ def test_external_nested_repeater(get_contract, typ, val):
     code = f"""
 @external
 def foo(a: {typ}) -> {typ}:
-    for i in range(10):
-        for x in range(10):
+    for i: {typ} in range(10):
+        for x: {typ} in range(10):
             if i + x > a:
                 return i + x
     return 31337
@@ -268,8 +268,8 @@ def test_external_void_nested_repeater(get_contract, typ, val):
 result: public({typ})
 @external
 def foo(a: {typ}):
-    for i in range(10):
-        for x in range(10):
+    for i: {typ} in range(10):
+        for x: {typ} in range(10):
             if i + x > a:
                 self.result = i + x
                 return
@@ -288,8 +288,8 @@ def test_breaks_and_returns_inside_nested_repeater(get_contract, typ):
     code = f"""
 @internal
 def _final(a: {typ}) -> {typ}:
-    for i in range(10):
-        for x in range(10):
+    for i: {typ} in range(10):
+        for x: {typ} in range(10):
             if a < 2:
                 break
             return 6