diff --git a/tests/parser/types/numbers/test_decimals.py b/tests/parser/types/numbers/test_decimals.py
index 876d711154..1418eab063 100644
--- a/tests/parser/types/numbers/test_decimals.py
+++ b/tests/parser/types/numbers/test_decimals.py
@@ -3,7 +3,7 @@
 
 import pytest
 
-from vyper.exceptions import DecimalOverrideException, InvalidOperation
+from vyper.exceptions import DecimalOverrideException, InvalidOperation, TypeMismatch
 from vyper.utils import DECIMAL_EPSILON, SizeLimits
 
 
@@ -261,4 +261,4 @@ def foo() -> decimal:
     return 2.2 ** 2.0
     """
 
-    assert_compile_failed(lambda: get_contract(code), InvalidOperation)
+    assert_compile_failed(lambda: get_contract(code), TypeMismatch)
diff --git a/vyper/builtins/functions.py b/vyper/builtins/functions.py
index 0898712407..7e57555b08 100644
--- a/vyper/builtins/functions.py
+++ b/vyper/builtins/functions.py
@@ -1088,9 +1088,9 @@ def fetch_call_return(self, node):
         if revert_on_failure is not None:
             revert_on_failure = get_folded_value(revert_on_failure)
 
-        revert_on_failure = revert_on_failure if revert_on_failure is not None else True
+        revert_on_failure = revert_on_failure.value if revert_on_failure is not None else True
 
-        if outsize is None or outsize == 0:
+        if outsize is None or outsize.value == 0:
             if revert_on_failure:
                 return None
             return BoolT()
diff --git a/vyper/semantics/analysis/pre_typecheck.py b/vyper/semantics/analysis/pre_typecheck.py
index 89ab20c5ff..98cfad06fb 100644
--- a/vyper/semantics/analysis/pre_typecheck.py
+++ b/vyper/semantics/analysis/pre_typecheck.py
@@ -68,7 +68,8 @@ def visit_FunctionDef(self, node):
         # visit type annotations of arguments
         # e.g. def foo(a: DynArray[uint256, 2 ** 8]): ...
         for arg in node.args.args:
-            self.visit(arg.annotation)
+            if arg.annotation:
+                self.visit(arg.annotation)
 
         for kwarg in node.args.defaults:
             self.visit(kwarg)
@@ -94,7 +95,7 @@ def visit_StructDef(self, node):
 
     def visit_VariableDecl(self, node):
         self.visit(node.annotation)
-        if node.is_constant:
+        if node.is_constant and node.value:
             self.visit(node.value)
 
     # Stmts
@@ -156,7 +157,7 @@ def visit_Attribute(self, node):
         self.visit(node.value)
         value_node = get_folded_value(node.value)
         if isinstance(value_node, vy_ast.Dict):
-            for k, v in zip(node.keys, node.values):
+            for k, v in zip(value_node.keys, value_node.values):
                 if k.id == node.attr:
                     node._metadata["folded_value"] = v
                     return
@@ -168,6 +169,10 @@ def visit_BinOp(self, node):
         left = get_folded_value(node.left)
         right = get_folded_value(node.right)
         if isinstance(left, type(right)) and isinstance(left, (vy_ast.Int, vy_ast.Decimal)):
+            if isinstance(node.op, (vy_ast.LShift, vy_ast.RShift)) and not (
+                0 <= right.value <= 256
+            ):
+                return
             value = node.op._op(left.value, right.value)
             node._metadata["folded_value"] = type(left).from_node(node, value=value)