diff --git a/include/components/builder.hpp b/include/components/builder.hpp
index 9b45a7eb..eac5afac 100644
--- a/include/components/builder.hpp
+++ b/include/components/builder.hpp
@@ -20,7 +20,7 @@ using namespace drawtypes;
 
 class builder {
  public:
-  explicit builder(const bar_settings bar);
+  explicit builder(const bar_settings& bar);
 
   string flush();
   void append(string text);
diff --git a/include/components/controller.hpp b/include/components/controller.hpp
index a1ae93af..e62b9c75 100644
--- a/include/components/controller.hpp
+++ b/include/components/controller.hpp
@@ -57,7 +57,7 @@ class controller : public signal_receiver<SIGN_PRIORITY_CONTROLLER, sig_ev::exit
   bool run(bool writeback = false);
 
   bool enqueue(event&& evt);
-  bool enqueue(string&& input);
+  bool enqueue(string&& input_data);
 
  protected:
   void read_events();
diff --git a/include/drawtypes/label.hpp b/include/drawtypes/label.hpp
index fe82eed4..70866bb7 100644
--- a/include/drawtypes/label.hpp
+++ b/include/drawtypes/label.hpp
@@ -14,9 +14,9 @@ POLYBAR_NS
 namespace drawtypes {
   struct token {
     string token;
-    size_t min;
-    size_t max;
-    string suffix{""};
+    size_t min{0_z};
+    size_t max{0_z};
+    string suffix{""s};
   };
 
   class label;
@@ -35,15 +35,15 @@ namespace drawtypes {
     string m_underline{};
     string m_overline{};
     int m_font{0};
-    side_values m_padding{0,0};
-    side_values m_margin{0,0};
-    size_t m_maxlen{0};
+    side_values m_padding{0U,0U};
+    side_values m_margin{0U,0U};
+    size_t m_maxlen{0_z};
     bool m_ellipsis{true};
 
     explicit label(string text, int font) : m_font(font), m_text(text), m_tokenized(m_text) {}
-    explicit label(string text, string foreground = "", string background = "", string underline = "",
-        string overline = "", int font = 0, struct side_values padding = {0,0}, struct side_values margin = {0,0},
-        size_t maxlen = 0, bool ellipsis = true, vector<token>&& tokens = {})
+    explicit label(string text, string foreground = ""s, string background = ""s, string underline = ""s,
+        string overline = ""s, int font = 0, struct side_values padding = {0U,0U}, struct side_values margin = {0U,0U},
+        size_t maxlen = 0_z, bool ellipsis = true, vector<token>&& tokens = {})
         : m_foreground(foreground)
         , m_background(background)
         , m_underline(underline)
@@ -72,11 +72,11 @@ namespace drawtypes {
     const vector<token> m_tokens{};
   };
 
-  label_t load_label(const config& conf, const string& section, string name, bool required = true, string def = "");
-  label_t load_optional_label(const config& conf, string section, string name, string def = "");
+  label_t load_label(const config& conf, const string& section, string name, bool required = true, string def = ""s);
+  label_t load_optional_label(const config& conf, string section, string name, string def = ""s);
 
-  icon_t load_icon(const config& conf, string section, string name, bool required = true, string def = "");
-  icon_t load_optional_icon(const config& conf, string section, string name, string def = "");
+  icon_t load_icon(const config& conf, string section, string name, bool required = true, string def = ""s);
+  icon_t load_optional_icon(const config& conf, string section, string name, string def = ""s);
 }
 
 POLYBAR_NS_END
diff --git a/include/utils/file.hpp b/include/utils/file.hpp
index b8a5eb3e..8f894a8b 100644
--- a/include/utils/file.hpp
+++ b/include/utils/file.hpp
@@ -66,8 +66,8 @@ class fd_streambuf : public std::streambuf {
 
  private:
   file_descriptor m_fd;
-  char m_out[BUFSIZ];
-  char m_in[BUFSIZ - 1];
+  char m_out[BUFSIZ]{'\0'};
+  char m_in[BUFSIZ - 1]{'\0'};
 };
 
 template <typename StreamType = std::ostream>
diff --git a/src/components/builder.cpp b/src/components/builder.cpp
index e229a228..f66fbc9c 100644
--- a/src/components/builder.cpp
+++ b/src/components/builder.cpp
@@ -12,7 +12,7 @@ POLYBAR_NS
 #define BUILDER_SPACE_TOKEN "%__"
 #endif
 
-builder::builder(const bar_settings bar) : m_bar(bar) {
+builder::builder(const bar_settings& bar) : m_bar(bar) {
   m_tags[syntaxtag::A] = 0;
   m_tags[syntaxtag::B] = 0;
   m_tags[syntaxtag::F] = 0;
@@ -311,7 +311,7 @@ void builder::space() {
  * Remove trailing space
  */
 void builder::remove_trailing_space(size_t len) {
-  if (len == 0_z  || len > m_output.size()) {
+  if (len == 0_z || len > m_output.size()) {
     return;
   } else if (m_output.substr(m_output.size() - len) == string(len, ' ')) {
     m_output.erase(m_output.size() - len);
diff --git a/src/components/logger.cpp b/src/components/logger.cpp
index 04ee0b63..3758b831 100644
--- a/src/components/logger.cpp
+++ b/src/components/logger.cpp
@@ -11,7 +11,7 @@ POLYBAR_NS
 /**
  * Convert string
  */
-const char* logger::convert(string arg) const {
+const char* logger::convert(string arg) const {  // NOLINT
   return arg.c_str();
 }
 
diff --git a/src/drawtypes/label.cpp b/src/drawtypes/label.cpp
index 4f6e7eea..865f6d4c 100644
--- a/src/drawtypes/label.cpp
+++ b/src/drawtypes/label.cpp
@@ -39,10 +39,10 @@ namespace drawtypes {
 
     for (auto&& tok : m_tokens) {
       if (token == tok.token) {
-        if (tok.max != 0 && replacement.length() > tok.max) {
+        if (tok.max != 0_z && replacement.length() > tok.max) {
           replacement = replacement.erase(tok.max) + tok.suffix;
-        } else if (tok.min != 0 && replacement.length() < tok.min) {
-          replacement.insert(0, tok.min - replacement.length(), ' ');
+        } else if (tok.min != 0_z && replacement.length() < tok.min) {
+          replacement.insert(0_z, tok.min - replacement.length(), ' ');
         }
         m_tokenized = string_util::replace_all(m_tokenized, token, move(replacement));
       }
@@ -65,19 +65,19 @@ namespace drawtypes {
     if (label->m_font != 0) {
       m_font = label->m_font;
     }
-    if (label->m_padding.left != 0) {
+    if (label->m_padding.left != 0U) {
       m_padding.left = label->m_padding.left;
     }
-    if (label->m_padding.right != 0) {
+    if (label->m_padding.right != 0U) {
       m_padding.right = label->m_padding.right;
     }
-    if (label->m_margin.left != 0) {
+    if (label->m_margin.left != 0U) {
       m_margin.left = label->m_margin.left;
     }
-    if (label->m_margin.right != 0) {
+    if (label->m_margin.right != 0U) {
       m_margin.right = label->m_margin.right;
     }
-    if (label->m_maxlen != 0) {
+    if (label->m_maxlen != 0_z) {
       m_maxlen = label->m_maxlen;
       m_ellipsis = label->m_ellipsis;
     }
@@ -99,19 +99,19 @@ namespace drawtypes {
     if (m_font == 0 && label->m_font != 0) {
       m_font = label->m_font;
     }
-    if (m_padding.left == 0 && label->m_padding.left != 0) {
+    if (m_padding.left == 0U && label->m_padding.left != 0U) {
       m_padding.left = label->m_padding.left;
     }
-    if (m_padding.right == 0 && label->m_padding.right != 0) {
+    if (m_padding.right == 0U && label->m_padding.right != 0U) {
       m_padding.right = label->m_padding.right;
     }
-    if (m_margin.left == 0 && label->m_margin.left != 0) {
+    if (m_margin.left == 0U && label->m_margin.left != 0U) {
       m_margin.left = label->m_margin.left;
     }
-    if (m_margin.right == 0 && label->m_margin.right != 0) {
+    if (m_margin.right == 0U && label->m_margin.right != 0U) {
       m_margin.right = label->m_margin.right;
     }
-    if (m_maxlen == 0 && label->m_maxlen != 0) {
+    if (m_maxlen == 0_z && label->m_maxlen != 0_z) {
       m_maxlen = label->m_maxlen;
       m_ellipsis = label->m_ellipsis;
     }
@@ -144,7 +144,7 @@ namespace drawtypes {
     }
 
     const auto get_left_right = [&](string key) {
-      auto value = conf.get(section, key, 0);
+      auto value = conf.get(section, key, 0U);
       auto left = conf.get(section, key + "-left", value);
       auto right = conf.get(section, key + "-right", value);
       return side_values{static_cast<uint16_t>(left), static_cast<uint16_t>(right)};
@@ -165,7 +165,7 @@ namespace drawtypes {
       }
 
       line.erase(start, end - start + 1);
-      tokens.emplace_back(token{token_str, 0, 0});
+      tokens.emplace_back(token{token_str, 0_z, 0_z});
       auto& token = tokens.back();
 
       // find min delimiter
@@ -196,7 +196,7 @@ namespace drawtypes {
 
       // ignore max lengths less than min
       if (token.max < token.min) {
-        token.max = 0;
+        token.max = 0_z;
       }
 
       // find suffix delimiter
diff --git a/src/modules/memory.cpp b/src/modules/memory.cpp
index 77e553ce..3aa9ae9a 100644
--- a/src/modules/memory.cpp
+++ b/src/modules/memory.cpp
@@ -1,6 +1,6 @@
 #include <fstream>
-#include <istream>
 #include <iomanip>
+#include <istream>
 
 #include "modules/memory.hpp"
 
diff --git a/src/modules/meta/base.cpp b/src/modules/meta/base.cpp
index ef782035..befa3cd7 100644
--- a/src/modules/meta/base.cpp
+++ b/src/modules/meta/base.cpp
@@ -104,7 +104,7 @@ namespace modules {
       } else if (find(whitelist.begin(), whitelist.end(), tag) != whitelist.end()) {
         continue;
       } else {
-        throw undefined_format_tag(tag + " is not a valid format tag for \""+ name +"\"");
+        throw undefined_format_tag(tag + " is not a valid format tag for \"" + name + "\"");
       }
     }