diff --git a/.clang-tidy b/.clang-tidy
index 34239d6b..f9617a2f 100644
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -11,6 +11,7 @@ clang-analyzer-*,
 -google-runtime-references,
 -misc-non-private-member-variables-in-classes,
 -readability-braces-around-statements,
+-readability-identifier-length,
 -google-readability-braces-around-statements,
 -cppcoreguidelines-avoid-magic-numbers,
 -readability-magic-numbers,
@@ -21,7 +22,8 @@ clang-analyzer-*,
 -modernize-avoid-c-arrays,
 -cppcoreguidelines-pro-bounds-array-to-pointer-decay,
 -readability-named-parameter,
--cert-env33-c
+-cert-env33-c,
+-modernize-concat-nested-namespaces
 '
 
 
diff --git a/include/spdlog/spdlog.h b/include/spdlog/spdlog.h
index a283ae1e..f724b01f 100644
--- a/include/spdlog/spdlog.h
+++ b/include/spdlog/spdlog.h
@@ -65,7 +65,7 @@ SPDLOG_API level get_level();
 SPDLOG_API void set_level(level level);
 
 // Determine whether the default logger should log messages with a certain level
-SPDLOG_API bool should_log(level lvl);
+SPDLOG_API bool should_log(level level);
 
 // Set global flush level
 SPDLOG_API void flush_on(level level);
diff --git a/src/details/file_helper.cpp b/src/details/file_helper.cpp
index df93d885..42ae3533 100644
--- a/src/details/file_helper.cpp
+++ b/src/details/file_helper.cpp
@@ -23,8 +23,8 @@ void file_helper::open(const filename_t &fname, bool truncate) {
     close();
     filename_ = fname;
 
-    auto *mode = SPDLOG_FILENAME_T("ab");
-    auto *trunc_mode = SPDLOG_FILENAME_T("wb");
+    const auto *mode = SPDLOG_FILENAME_T("ab");
+    const auto *trunc_mode = SPDLOG_FILENAME_T("wb");
 
     if (event_handlers_.before_open) {
         event_handlers_.before_open(filename_);
@@ -37,7 +37,7 @@ void file_helper::open(const filename_t &fname, bool truncate) {
             // opening the actual log-we-write-to in "ab" mode, since that
             // interacts more politely with eternal processes that might
             // rotate/truncate the file underneath us.
-            std::FILE *tmp;
+            std::FILE *tmp = nullptr;
             if (os::fopen_s(&tmp, fname, trunc_mode)) {
                 continue;
             }
@@ -93,7 +93,7 @@ void file_helper::close() {
 void file_helper::write(const memory_buf_t &buf) {
     if (fd_ == nullptr) return;
     size_t msg_size = buf.size();
-    auto data = buf.data();
+    const auto *data = buf.data();
     if (std::fwrite(data, 1, msg_size, fd_) != msg_size) {
         throw_spdlog_ex("Failed writing to file " + os::filename_to_str(filename_), errno);
     }
diff --git a/src/details/os.cpp b/src/details/os.cpp
index eafc60ce..94356c76 100644
--- a/src/details/os.cpp
+++ b/src/details/os.cpp
@@ -84,12 +84,12 @@ spdlog::log_clock::time_point now() noexcept {
 #endif
 }
 std::tm localtime(const std::time_t &time_tt) noexcept {
-    std::tm* rv;
-    std::tm tm;
 #ifdef _WIN32
-    rv = ::localtime_s(&tm, &time_tt);
+    std::tm tm;
+    const auto *rv = ::localtime_s(&tm, &time_tt);
 #else
-    rv = ::localtime_r(&time_tt, &tm);
+    std::tm tm;
+    const auto *rv = ::localtime_r(&time_tt, &tm);
 #endif
     return rv != nullptr ? tm : std::tm{};
 }
@@ -548,7 +548,7 @@ std::string getenv(const char *field) {
     #endif
 #else  // revert to getenv
     char *buf = ::getenv(field);
-    return buf ? buf : std::string{};
+    return buf != nullptr ? buf : std::string{};
 #endif
 }