diff --git a/python/mach/mach/command_util.py b/python/mach/mach/command_util.py
index 44e13f18d6cc..14bf65d60257 100644
--- a/python/mach/mach/command_util.py
+++ b/python/mach/mach/command_util.py
@@ -292,14 +292,14 @@ class DecoratorVisitor(ast.NodeVisitor):
             kwarg_dict = {}
 
             for name, arg in zip(["command", "subcommand"], decorator.args):
-                kwarg_dict[name] = arg.s
+                kwarg_dict[name] = arg.value
 
             for keyword in decorator.keywords:
                 if keyword.arg not in relevant_kwargs:
                     # We only care about these 3 kwargs, so we can safely skip the rest
                     continue
 
-                kwarg_dict[keyword.arg] = getattr(keyword.value, "s", "")
+                kwarg_dict[keyword.arg] = keyword.value.value
 
             command = kwarg_dict.pop("command")
             self.results.setdefault(command, {})
diff --git a/python/mach/mach/dispatcher.py b/python/mach/mach/dispatcher.py
index abc3b646c6f8..54b0f9494f17 100644
--- a/python/mach/mach/dispatcher.py
+++ b/python/mach/mach/dispatcher.py
@@ -289,16 +289,14 @@ class CommandAction(argparse.Action):
                     group = parser.add_argument_group(title, description)
 
                 description = handler.description
-                group.add_argument(command, help=description, action="store_true")
+                group.add_argument(command, help=description)
 
         if disabled_commands and "disabled" in r.categories:
             title, description, _priority = r.categories["disabled"]
             group = parser.add_argument_group(title, description)
             if verbose:
                 for c in disabled_commands:
-                    group.add_argument(
-                        c["command"], help=c["description"], action="store_true"
-                    )
+                    group.add_argument(c["command"], help=c["description"])
 
         parser.print_help()
 
@@ -405,9 +403,7 @@ class CommandAction(argparse.Action):
             subhandlers,
             key=by_decl_order if handler.order == "declaration" else by_name,
         ):
-            group.add_argument(
-                subcommand, help=subhandler.description, action="store_true"
-            )
+            group.add_argument(subcommand, help=subhandler.description)
 
         if handler.docstring:
             parser.description = format_docstring(handler.docstring)
diff --git a/python/mozbuild/mozbuild/frontend/reader.py b/python/mozbuild/mozbuild/frontend/reader.py
index 9f6292cb909d..89bf9995c176 100644
--- a/python/mozbuild/mozbuild/frontend/reader.py
+++ b/python/mozbuild/mozbuild/frontend/reader.py
@@ -470,7 +470,7 @@ class TemplateFunction:
             return c(
                 ast.Subscript(
                     value=c(ast.Name(id=self._global_name, ctx=ast.Load())),
-                    slice=c(ast.Index(value=c(ast.Str(s=node.id)))),
+                    slice=c(ast.Index(value=c(ast.Constant(value=node.id)))),
                     ctx=node.ctx,
                 )
             )
@@ -1039,8 +1039,8 @@ class BuildReader:
                 else:
                     # Others
                     assert isinstance(target.slice, ast.Index)
-                    assert isinstance(target.slice.value, ast.Str)
-                    key = target.slice.value.s
+                    assert isinstance(target.slice.value, ast.Constant)
+                    key = target.slice.value.value
             elif isinstance(target, ast.Attribute):
                 assert isinstance(target.attr, str)
                 key = target.attr
@@ -1051,11 +1051,11 @@ class BuildReader:
             value = node.value
             if isinstance(value, ast.List):
                 for v in value.elts:
-                    assert isinstance(v, ast.Str)
-                    yield v.s
+                    assert isinstance(v, ast.Constant)
+                    yield v.value
             else:
-                assert isinstance(value, ast.Str)
-                yield value.s
+                assert isinstance(value, ast.Constant)
+                yield value.value
 
         assignments = []
 
diff --git a/python/mozbuild/mozbuild/vendor/rewrite_mozbuild.py b/python/mozbuild/mozbuild/vendor/rewrite_mozbuild.py
index cfcc0f18b9a9..de06b58819b6 100644
--- a/python/mozbuild/mozbuild/vendor/rewrite_mozbuild.py
+++ b/python/mozbuild/mozbuild/vendor/rewrite_mozbuild.py
@@ -327,15 +327,13 @@ def assignment_node_to_source_filename_list(code, node):
     """
     if isinstance(node.value, ast.List) and "elts" in node.value._fields:
         for f in node.value.elts:
-            if not isinstance(f, ast.Constant) and not isinstance(f, ast.Str):
+            if not isinstance(f, ast.Constant):
                 log(
                     "Found non-constant source file name in list: ",
                     ast_get_source_segment(code, f),
                 )
                 return []
-        return [
-            f.value if isinstance(f, ast.Constant) else f.s for f in node.value.elts
-        ]
+        return [f.value for f in node.value.elts]
     elif isinstance(node.value, ast.ListComp):
         # SOURCES += [f for f in foo if blah]
         log("Could not find the files for " + ast_get_source_segment(code, node.value))
diff --git a/python/mozbuild/mozbuild/vendor/vendor_python.py b/python/mozbuild/mozbuild/vendor/vendor_python.py
index 9acee946fc4c..2801e1b685d5 100644
--- a/python/mozbuild/mozbuild/vendor/vendor_python.py
+++ b/python/mozbuild/mozbuild/vendor/vendor_python.py
@@ -40,6 +40,10 @@ EXCLUDED_PACKAGES = {
     # modified 'dummy' version of it so that the dependency checks still succeed, but
     # if it ever is attempted to be used, it will fail gracefully.
     "ansicon",
+    # jsonschema 4.17.3 is incompatible with Python 3.14+,
+    # but later versions use a dependency with Rust components, which we thus can't vendor.
+    # For now we apply the minimal patch to jsonschema to make it work again.
+    "jsonschema",
 }
 
 
diff --git a/third_party/python/jsonschema/jsonschema/validators.py b/third_party/python/jsonschema/jsonschema/validators.py
index 66e803ea2d0b..88316a8bb727 100644
--- a/third_party/python/jsonschema/jsonschema/validators.py
+++ b/third_party/python/jsonschema/jsonschema/validators.py
@@ -875,8 +875,11 @@ class RefResolver:
             return None
         uri, fragment = urldefrag(url)
         for subschema in subschemas:
+            id = subschema["$id"]
+            if not isinstance(id, str):
+                continue
             target_uri = self._urljoin_cache(
-                self.resolution_scope, subschema["$id"],
+                self.resolution_scope, id,
             )
             if target_uri.rstrip("/") == uri.rstrip("/"):
                 if fragment: