diff --git a/ostd/format.hh b/ostd/format.hh
index 2de816f..50c5524 100644
--- a/ostd/format.hh
+++ b/ostd/format.hh
@@ -180,7 +180,7 @@ namespace detail {
     };
 
     inline char const *escape_fmt_char(char v, char quote) {
-        if ((v >= 0 && v < 0x20) || (v == quote)) {
+        if ((static_cast<unsigned char>(v) < 0x20) || (v == quote)) {
             return fmt_escapes[std::size_t(v)];
         } else if (v == 0x7F) {
             return "\\x7F";
diff --git a/ostd/path.hh b/ostd/path.hh
index c5d97a9..f9c431e 100644
--- a/ostd/path.hh
+++ b/ostd/path.hh
@@ -225,13 +225,13 @@ struct path {
      * the path are reset and the path is started over.
      */
     template<typename R>
-    path(R range, format fmt = format::native):
+    path(R irange, format fmt = format::native):
         p_path("."), p_fmt(path_fmt(fmt))
     {
         if constexpr(std::is_constructible_v<std::string, R const &>) {
-            append_str(std::string{range});
-        } else if (!range.empty()) {
-            for (auto const &elem: range) {
+            append_str(std::string{irange});
+        } else if (!irange.empty()) {
+            for (auto const &elem: irange) {
                 append_str(std::string{elem});
             }
         }
@@ -333,19 +333,19 @@ struct path {
      */
     string_range drive() const noexcept {
         if (is_win()) {
-            string_range path = p_path;
-            if (has_dslash(path)) {
+            string_range tpath = p_path;
+            if (has_dslash(tpath)) {
                 char const *endp = strchr(p_path.data() + 2, '\\');
                 if (!endp) {
-                    return path;
+                    return tpath;
                 }
                 char const *pendp = strchr(endp + 1, '\\');
                 if (!pendp) {
-                    return path;
+                    return tpath;
                 }
-                return string_range{path.data(), pendp};
-            } else if (has_letter(path)) {
-                return path.slice(0, 2);
+                return string_range{tpath.data(), pendp};
+            } else if (has_letter(tpath)) {
+                return tpath.slice(0, 2);
             }
         }
         return nullptr;
diff --git a/src/posix/path.cc b/src/posix/path.cc
index 65c1760..20e3921 100644
--- a/src/posix/path.cc
+++ b/src/posix/path.cc
@@ -113,7 +113,7 @@ static file_status status_get(path const &p, int ret, struct stat &sb) {
         throw fs_error{"stat failure", p, errno_ec()};
     }
     return file_status{
-        file_mode{mode_to_type(sb.st_mode), perms{sb.st_mode & 07777}},
+        file_mode{mode_to_type(sb.st_mode), perms{int(sb.st_mode) & 07777}},
         mtime::get(sb),
         std::uintmax_t(sb.st_size),
         std::uintmax_t(sb.st_nlink)