diff --git a/vm/src/stdlib/ast.rs b/vm/src/stdlib/ast.rs
index 5512fb383..107cc0ac9 100644
--- a/vm/src/stdlib/ast.rs
+++ b/vm/src/stdlib/ast.rs
@@ -610,20 +610,23 @@ fn ast_parse(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
 }
 
 pub fn mk_module(ctx: &PyContext) -> PyObjectRef {
+    // TODO: maybe we can use some clever macro to generate this?
     let ast_mod = ctx.new_module("ast", ctx.new_scope(None));
+
     ctx.set_attr(&ast_mod, "parse", ctx.new_rustfunc(ast_parse));
+
     ctx.set_attr(
         &ast_mod,
         "Module",
         ctx.new_class("_ast.Module", ctx.object()),
     );
 
-    // TODO: maybe we can use some clever macro to generate this?
     ctx.set_attr(
         &ast_mod,
         "FunctionDef",
         ctx.new_class("_ast.FunctionDef", ctx.object()),
     );
     ctx.set_attr(&ast_mod, "Call", ctx.new_class("_ast.Call", ctx.object()));
+
     ast_mod
 }
diff --git a/vm/src/stdlib/io.rs b/vm/src/stdlib/io.rs
index d504dd65e..c639195ec 100644
--- a/vm/src/stdlib/io.rs
+++ b/vm/src/stdlib/io.rs
@@ -359,7 +359,9 @@ pub fn io_open(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
 
 pub fn mk_module(ctx: &PyContext) -> PyObjectRef {
     let py_mod = ctx.new_module(&"io".to_string(), ctx.new_scope(None));
+
     ctx.set_attr(&py_mod, "open", ctx.new_rustfunc(io_open));
+
     //IOBase the abstract base class of the IO Module
     let io_base = ctx.new_class("IOBase", ctx.object());
     ctx.set_attr(&py_mod, "IOBase", io_base.clone());
@@ -368,64 +370,88 @@ pub fn mk_module(ctx: &PyContext) -> PyObjectRef {
     let raw_io_base = ctx.new_class("RawIOBase", ctx.object());
     ctx.set_attr(&py_mod, "RawIOBase", raw_io_base.clone());
 
-    let buffered_io_base = ctx.new_class("BufferedIOBase", io_base.clone());
-    ctx.set_attr(
-        &buffered_io_base,
-        "__init__",
-        ctx.new_rustfunc(buffered_io_base_init),
-    );
+    let buffered_io_base = {
+        let buffered_io_base = ctx.new_class("BufferedIOBase", io_base.clone());
+        ctx.set_attr(
+            &buffered_io_base,
+            "__init__",
+            ctx.new_rustfunc(buffered_io_base_init),
+        );
+        buffered_io_base
+    };
     ctx.set_attr(&py_mod, "BufferedIOBase", buffered_io_base.clone());
 
     //TextIO Base has no public constructor
-    let text_io_base = ctx.new_class("TextIOBase", io_base.clone());
-    ctx.set_attr(&text_io_base, "read", ctx.new_rustfunc(text_io_base_read));
+    let text_io_base = {
+        let text_io_base = ctx.new_class("TextIOBase", io_base.clone());
+        ctx.set_attr(&text_io_base, "read", ctx.new_rustfunc(text_io_base_read));
+        text_io_base
+    };
     ctx.set_attr(&py_mod, "TextIOBase", text_io_base.clone());
 
     // RawBaseIO Subclasses
-    let file_io = ctx.new_class("FileIO", raw_io_base.clone());
-    ctx.set_attr(&file_io, "__init__", ctx.new_rustfunc(file_io_init));
-    ctx.set_attr(&file_io, "name", ctx.str_type());
-    ctx.set_attr(&file_io, "read", ctx.new_rustfunc(file_io_read));
-    ctx.set_attr(&file_io, "readinto", ctx.new_rustfunc(file_io_readinto));
-    ctx.set_attr(&file_io, "write", ctx.new_rustfunc(file_io_write));
+    let file_io = {
+        let file_io = ctx.new_class("FileIO", raw_io_base.clone());
+        ctx.set_attr(&file_io, "__init__", ctx.new_rustfunc(file_io_init));
+        ctx.set_attr(&file_io, "name", ctx.str_type());
+        ctx.set_attr(&file_io, "read", ctx.new_rustfunc(file_io_read));
+        ctx.set_attr(&file_io, "readinto", ctx.new_rustfunc(file_io_readinto));
+        ctx.set_attr(&file_io, "write", ctx.new_rustfunc(file_io_write));
+        file_io
+    };
     ctx.set_attr(&py_mod, "FileIO", file_io.clone());
 
     // BufferedIOBase Subclasses
-    let buffered_reader = ctx.new_class("BufferedReader", buffered_io_base.clone());
-    ctx.set_attr(
-        &buffered_reader,
-        "read",
-        ctx.new_rustfunc(buffered_reader_read),
-    );
+    let buffered_reader = {
+        let buffered_reader = ctx.new_class("BufferedReader", buffered_io_base.clone());
+        ctx.set_attr(
+            &buffered_reader,
+            "read",
+            ctx.new_rustfunc(buffered_reader_read),
+        );
+        buffered_reader
+    };
     ctx.set_attr(&py_mod, "BufferedReader", buffered_reader.clone());
 
-    let buffered_writer = ctx.new_class("BufferedWriter", buffered_io_base.clone());
-    ctx.set_attr(
-        &buffered_writer,
-        "write",
-        ctx.new_rustfunc(buffered_writer_write),
-    );
+    let buffered_writer = {
+        let buffered_writer = ctx.new_class("BufferedWriter", buffered_io_base.clone());
+        ctx.set_attr(
+            &buffered_writer,
+            "write",
+            ctx.new_rustfunc(buffered_writer_write),
+        );
+        buffered_writer
+    };
     ctx.set_attr(&py_mod, "BufferedWriter", buffered_writer.clone());
 
     //TextIOBase Subclass
-    let text_io_wrapper = ctx.new_class("TextIOWrapper", text_io_base.clone());
-    ctx.set_attr(
-        &text_io_wrapper,
-        "__init__",
-        ctx.new_rustfunc(text_io_wrapper_init),
-    );
+    let text_io_wrapper = {
+        let text_io_wrapper = ctx.new_class("TextIOWrapper", text_io_base.clone());
+        ctx.set_attr(
+            &text_io_wrapper,
+            "__init__",
+            ctx.new_rustfunc(text_io_wrapper_init),
+        );
+        text_io_wrapper
+    };
     ctx.set_attr(&py_mod, "TextIOWrapper", text_io_wrapper.clone());
 
     // BytesIO: in-memory bytes
-    let string_io = ctx.new_class("StringIO", io_base.clone());
-    ctx.set_attr(&string_io, "__init__", ctx.new_rustfunc(string_io_init));
-    ctx.set_attr(&string_io, "getvalue", ctx.new_rustfunc(string_io_getvalue));
+    let string_io = {
+        let string_io = ctx.new_class("StringIO", io_base.clone());
+        ctx.set_attr(&string_io, "__init__", ctx.new_rustfunc(string_io_init));
+        ctx.set_attr(&string_io, "getvalue", ctx.new_rustfunc(string_io_getvalue));
+        string_io
+    };
     ctx.set_attr(&py_mod, "StringIO", string_io);
 
     // StringIO: in-memory text
-    let bytes_io = ctx.new_class("BytesIO", io_base.clone());
-    ctx.set_attr(&bytes_io, "__init__", ctx.new_rustfunc(bytes_io_init));
-    ctx.set_attr(&bytes_io, "getvalue", ctx.new_rustfunc(bytes_io_getvalue));
+    let bytes_io = {
+        let bytes_io = ctx.new_class("BytesIO", io_base.clone());
+        ctx.set_attr(&bytes_io, "__init__", ctx.new_rustfunc(bytes_io_init));
+        ctx.set_attr(&bytes_io, "getvalue", ctx.new_rustfunc(bytes_io_getvalue));
+        bytes_io
+    };
     ctx.set_attr(&py_mod, "BytesIO", bytes_io);
 
     py_mod
diff --git a/vm/src/stdlib/json.rs b/vm/src/stdlib/json.rs
index 98d260538..1101a8713 100644
--- a/vm/src/stdlib/json.rs
+++ b/vm/src/stdlib/json.rs
@@ -233,8 +233,10 @@ fn loads(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
 
 pub fn mk_module(ctx: &PyContext) -> PyObjectRef {
     let json_mod = ctx.new_module("json", ctx.new_scope(None));
+
     ctx.set_attr(&json_mod, "dumps", ctx.new_rustfunc(dumps));
     ctx.set_attr(&json_mod, "loads", ctx.new_rustfunc(loads));
+
     // TODO: Make this a proper type with a constructor
     let json_decode_error = create_type(
         "JSONDecodeError",
@@ -243,5 +245,6 @@ pub fn mk_module(ctx: &PyContext) -> PyObjectRef {
         &ctx.dict_type,
     );
     ctx.set_attr(&json_mod, "JSONDecodeError", json_decode_error);
+
     json_mod
 }
diff --git a/vm/src/stdlib/keyword.rs b/vm/src/stdlib/keyword.rs
index 9564095ce..c34876c56 100644
--- a/vm/src/stdlib/keyword.rs
+++ b/vm/src/stdlib/keyword.rs
@@ -19,7 +19,9 @@ fn keyword_iskeyword(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
 
 pub fn mk_module(ctx: &PyContext) -> PyObjectRef {
     let py_mod = ctx.new_module("keyword", ctx.new_scope(None));
+
     ctx.set_attr(&py_mod, "iskeyword", ctx.new_rustfunc(keyword_iskeyword));
+
     let keyword_kwlist = ctx.new_list(
         lexer::get_keywords()
             .keys()
@@ -27,5 +29,6 @@ pub fn mk_module(ctx: &PyContext) -> PyObjectRef {
             .collect(),
     );
     ctx.set_attr(&py_mod, "kwlist", keyword_kwlist);
+
     py_mod
 }
diff --git a/vm/src/stdlib/pystruct.rs b/vm/src/stdlib/pystruct.rs
index 8e0ecc580..fda1854f4 100644
--- a/vm/src/stdlib/pystruct.rs
+++ b/vm/src/stdlib/pystruct.rs
@@ -342,7 +342,9 @@ fn struct_unpack(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
 
 pub fn mk_module(ctx: &PyContext) -> PyObjectRef {
     let py_mod = ctx.new_module(&"struct".to_string(), ctx.new_scope(None));
+
     ctx.set_attr(&py_mod, "pack", ctx.new_rustfunc(struct_pack));
     ctx.set_attr(&py_mod, "unpack", ctx.new_rustfunc(struct_unpack));
+
     py_mod
 }
diff --git a/vm/src/stdlib/re.rs b/vm/src/stdlib/re.rs
index 5ccd15524..d05c50e0f 100644
--- a/vm/src/stdlib/re.rs
+++ b/vm/src/stdlib/re.rs
@@ -51,9 +51,12 @@ fn re_search(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
 
 pub fn mk_module(ctx: &PyContext) -> PyObjectRef {
     let py_mod = ctx.new_module("re", ctx.new_scope(None));
+
     let match_type = ctx.new_class("Match", ctx.object());
     ctx.set_attr(&py_mod, "Match", match_type);
+
     ctx.set_attr(&py_mod, "match", ctx.new_rustfunc(re_match));
     ctx.set_attr(&py_mod, "search", ctx.new_rustfunc(re_search));
+
     py_mod
 }
diff --git a/vm/src/stdlib/time_module.rs b/vm/src/stdlib/time_module.rs
index 1d21947ba..3c7976ede 100644
--- a/vm/src/stdlib/time_module.rs
+++ b/vm/src/stdlib/time_module.rs
@@ -32,7 +32,9 @@ fn time_time(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
 
 pub fn mk_module(ctx: &PyContext) -> PyObjectRef {
     let py_mod = ctx.new_module("time", ctx.new_scope(None));
+
     ctx.set_attr(&py_mod, "sleep", ctx.new_rustfunc(time_sleep));
     ctx.set_attr(&py_mod, "time", ctx.new_rustfunc(time_time));
+
     py_mod
 }
diff --git a/vm/src/sysmodule.rs b/vm/src/sysmodule.rs
index ec48da745..e747fda5a 100644
--- a/vm/src/sysmodule.rs
+++ b/vm/src/sysmodule.rs
@@ -39,24 +39,38 @@ fn sys_getsizeof(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
 pub fn mk_module(ctx: &PyContext) -> PyObjectRef {
     let path_list = match env::var_os("PYTHONPATH") {
         Some(paths) => env::split_paths(&paths)
-            .map(|path| ctx.new_str(path.to_str().unwrap().to_string()))
+            .map(|path| {
+                ctx.new_str(
+                    path.to_str()
+                        .expect("PYTHONPATH isn't valid unicode")
+                        .to_string(),
+                )
+            })
             .collect(),
         None => vec![],
     };
     let path = ctx.new_list(path_list);
+
     let modules = ctx.new_dict();
+
     let sys_name = "sys";
     let sys_mod = ctx.new_module(&sys_name, ctx.new_scope(None));
+
     ctx.set_item(&modules, sys_name, sys_mod.clone());
+
     ctx.set_item(&sys_mod, "modules", modules);
     ctx.set_item(&sys_mod, "argv", argv(ctx));
     ctx.set_item(&sys_mod, "getrefcount", ctx.new_rustfunc(sys_getrefcount));
     ctx.set_item(&sys_mod, "getsizeof", ctx.new_rustfunc(sys_getsizeof));
-    let maxsize = ctx.new_int(std::usize::MAX.to_bigint().unwrap());
-    ctx.set_item(&sys_mod, "maxsize", maxsize);
+    ctx.set_item(
+        &sys_mod,
+        "maxsize",
+        ctx.new_int(std::usize::MAX.to_bigint().unwrap()),
+    );
     ctx.set_item(&sys_mod, "path", path);
     ctx.set_item(&sys_mod, "ps1", ctx.new_str(">>>>> ".to_string()));
     ctx.set_item(&sys_mod, "ps2", ctx.new_str("..... ".to_string()));
     ctx.set_item(&sys_mod, "_getframe", ctx.new_rustfunc(getframe));
+
     sys_mod
 }