diff --git a/src/function.cpp b/src/function.cpp
index f15b06739..bf32c2fe3 100644
--- a/src/function.cpp
+++ b/src/function.cpp
@@ -30,27 +30,26 @@
 #include "wutil.h"  // IWYU pragma: keep
 
 class function_info_t {
-public:
- /// Immutable properties of the function.
- std::shared_ptr<const function_properties_t> props;
- /// Function description. This may be changed after the function is created.
- wcstring description;
- /// File where this function was defined (intern'd string).
- const wchar_t *const definition_file;
- /// Mapping of all variables that were inherited from the function definition scope to their
- /// values.
- const std::map<wcstring, env_var_t> inherit_vars;
- /// Flag for specifying that this function was automatically loaded.
- const bool is_autoload;
+   public:
+    /// Immutable properties of the function.
+    std::shared_ptr<const function_properties_t> props;
+    /// Function description. This may be changed after the function is created.
+    wcstring description;
+    /// File where this function was defined (intern'd string).
+    const wchar_t *const definition_file;
+    /// Mapping of all variables that were inherited from the function definition scope to their
+    /// values.
+    const std::map<wcstring, env_var_t> inherit_vars;
+    /// Flag for specifying that this function was automatically loaded.
+    const bool is_autoload;
 
- /// Constructs relevant information from the function_data.
- function_info_t(function_data_t data, const wchar_t *filename, bool autoload);
+    /// Constructs relevant information from the function_data.
+    function_info_t(function_data_t data, const wchar_t *filename, bool autoload);
 
- /// Used by function_copy.
- function_info_t(const function_info_t &data, const wchar_t *filename, bool autoload);
+    /// Used by function_copy.
+    function_info_t(const function_info_t &data, const wchar_t *filename, bool autoload);
 };
 
-
 /// Table containing all functions.
 typedef std::unordered_map<wcstring, function_info_t> function_map_t;
 static function_map_t loaded_functions;
@@ -110,12 +109,11 @@ static void autoload_names(std::unordered_set<wcstring> &names, int get_hidden)
 
     for (i = 0; i < path_list.size(); i++) {
         const wcstring &ndir_str = path_list.at(i);
-        const wchar_t *ndir = (wchar_t *)ndir_str.c_str();
-        DIR *dir = wopendir(ndir);
-        if (!dir) continue;
+        dir_t dir(ndir_str);
+        if (!dir.valid()) continue;
 
         wcstring name;
-        while (wreaddir(dir, name)) {
+        while (dir.read(name)) {
             const wchar_t *fn = name.c_str();
             const wchar_t *suffix;
             if (!get_hidden && fn[0] == L'_') continue;
@@ -126,7 +124,6 @@ static void autoload_names(std::unordered_set<wcstring> &names, int get_hidden)
                 names.insert(name);
             }
         }
-        closedir(dir);
     }
 }
 
@@ -327,7 +324,8 @@ int function_get_definition_lineno(const wcstring &name) {
     scoped_rlock locker(functions_lock);
     const function_info_t *func = function_get(name);
     if (!func) return -1;
-    // return one plus the number of newlines at offsets less than the start of our function's statement (which includes the header).
+    // return one plus the number of newlines at offsets less than the start of our function's
+    // statement (which includes the header).
     // TODO: merge with line_offset_of_character_at_offset?
     auto block_stat = func->props->body_node.try_get_parent<grammar::block_statement>();
     assert(block_stat && "Function body is not part of block statement");
diff --git a/src/wutil.cpp b/src/wutil.cpp
index ee0bb03d6..51eaa44ca 100644
--- a/src/wutil.cpp
+++ b/src/wutil.cpp
@@ -235,6 +235,26 @@ DIR *wopendir(const wcstring &name) {
     return opendir(tmp.c_str());
 }
 
+dir_t::dir_t(const wcstring &path) {
+    const cstring tmp = wcs2string(path);
+    this->dir = opendir(tmp.c_str());
+}
+
+dir_t::~dir_t() {
+    if (this->dir != nullptr) {
+        closedir(this->dir);
+        this->dir = nullptr;
+    }
+}
+
+bool dir_t::valid() const {
+    return this->dir != nullptr;
+}
+
+bool dir_t::read(wcstring &name) {
+    return wreaddir(this->dir, name);
+}
+
 int wstat(const wcstring &file_name, struct stat *buf) {
     const cstring tmp = wcs2string(file_name);
     return stat(tmp.c_str(), buf);
diff --git a/src/wutil.h b/src/wutil.h
index c1af1e70e..055493432 100644
--- a/src/wutil.h
+++ b/src/wutil.h
@@ -152,6 +152,15 @@ struct file_id_t {
     int compare_file_id(const file_id_t &rhs) const;
 };
 
+/// RAII wrapper for DIR*
+struct dir_t {
+    DIR *dir;
+    bool valid() const;
+    bool read(wcstring &name);
+    dir_t(const wcstring &path);
+    ~dir_t();
+};
+
 #ifndef HASH_FILE_ID
 #define HASH_FILE_ID 1
 namespace std {