diff --git a/src/packagedcode/build.py b/src/packagedcode/build.py
index 2f2d964758..8044f8c245 100644
--- a/src/packagedcode/build.py
+++ b/src/packagedcode/build.py
@@ -163,14 +163,14 @@ def parse(cls, location, package_only=False):
                 args = {}
                 for kw in statement.value.keywords:
                     arg_name = kw.arg
-                    if isinstance(kw.value, ast.Str):
-                        args[arg_name] = kw.value.s
+                    if isinstance(kw.value, ast.Constant) and isinstance(kw.value.value, str):
+                        args[arg_name] = kw.value.value
 
                     if isinstance(kw.value, ast.List):
                         # We collect the elements of a list if the element is
                         # not a function call
                         args[arg_name] = [
-                            elt.s for elt in kw.value.elts
+                            elt.value for elt in kw.value.elts
                             if not isinstance(elt, ast.Call)
                         ]
                 if args:
@@ -351,17 +351,17 @@ def parse(cls, location, package_only=True):
                 statement_keys = statement.value.keys
                 statement_values = statement.value.values
                 for statement_k, statement_v in zip(statement_keys, statement_values):
-                    if isinstance(statement_k, ast.Str):
-                        key_name = statement_k.s
+                    if isinstance(statement_k, ast.Constant) and isinstance(statement_k.value, str):
+                        key_name = statement_k.value
                     # The list values in a `METADATA.bzl` file seem to only contain strings
                     if isinstance(statement_v, ast.List):
                         value = []
                         for e in statement_v.elts:
-                            if not isinstance(e, ast.Str):
+                            if not (isinstance(e, ast.Constant) and isinstance(e.value, str)):
                                 continue
-                            value.append(e.s)
-                    if isinstance(statement_v, (ast.Str, ast.Constant)):
-                        value = statement_v.s
+                            value.append(e.value)
+                    if isinstance(statement_v, ast.Constant):
+                        value = statement_v.value
                     metadata_fields[key_name] = value
 
         parties = []
diff --git a/src/packagedcode/pypi.py b/src/packagedcode/pypi.py
index 2610f43a01..761c149a40 100644
--- a/src/packagedcode/pypi.py
+++ b/src/packagedcode/pypi.py
@@ -2157,8 +2157,8 @@ def get_setup_py_args_legacy(location, include_not_parsable=False):
                         ]
                         values.append(val)
 
-                    elif isinstance(val, (ast.Str, ast.Constant,)):
-                        values.append(val.s)
+                    elif isinstance(val, ast.Constant):
+                        values.append(val.value)
 
                     else:
                         if include_not_parsable:
@@ -2183,8 +2183,8 @@ def get_setup_py_args_legacy(location, include_not_parsable=False):
                 mapping = dict(zip(keys, values))
                 setup_args[arg_name] = mapping
 
-            elif isinstance(arg_value, (ast.Str, ast.Constant,)):
-                setup_args[arg_name] = arg_value.s
+            elif isinstance(arg_value, ast.Constant):
+                setup_args[arg_name] = arg_value.value
             else:
                 if include_not_parsable:
                     if isinstance(arg_value, ast.Attribute):
diff --git a/src/packagedcode/pypi_setup_py.py b/src/packagedcode/pypi_setup_py.py
index 5e2559af12..51a94313d2 100644
--- a/src/packagedcode/pypi_setup_py.py
+++ b/src/packagedcode/pypi_setup_py.py
@@ -119,15 +119,9 @@ def node_to_value(node, body):
     """
     if node is None:
         return
-    if hasattr(ast, 'Constant'):
-        if isinstance(node, ast.Constant):
-            return node.value
 
-    if isinstance(node, ast.Str):
-        return node.s
-
-    if isinstance(node, ast.Num):
-        return node.n
+    if isinstance(node, ast.Constant):
+        return node.value
 
     if isinstance(node, (ast.List, ast.Tuple, ast.Set,)):
         return [node_to_value(subnode, body) for subnode in node.elts]