diff --git a/.github/workflows/clang-tidy.yml b/.github/workflows/clang-tidy.yml
index d747192..e9e06ba 100644
--- a/.github/workflows/clang-tidy.yml
+++ b/.github/workflows/clang-tidy.yml
@@ -5,10 +5,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: ZedThree/clang-tidy-review@v0.14.0
+      - uses: ZedThree/clang-tidy-review@v0.20.0
         id: review
         with:
           config_file: '.clang-tidy'
-          cmake_command: cmake . -D CMAKE_C_COMPILER=clang-16
+          cmake_command: cmake . -D CMAKE_C_COMPILER=clang-18
       - if: steps.review.outputs.total_comments > 0
         run: exit 1
diff --git a/.idea/misc.xml b/.idea/misc.xml
index d2e15db..5ebbd37 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -1,9 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
-  <component name="BackendCodeEditorMiscSettings">
-    <option name="/Default/Housekeeping/GlobalSettingsUpgraded/IsUpgraded/@EntryValue" value="true" type="bool" />
-    <option name="/Default/Environment/Hierarchy/GeneratedFilesCacheKey/Timestamp/@EntryValue" value="6" type="long" />
-  </component>
   <component name="CMakePythonSetting">
     <option name="pythonIntegrationState" value="YES" />
   </component>
diff --git a/src/main.c b/src/main.c
index aca2de2..d77cc78 100644
--- a/src/main.c
+++ b/src/main.c
@@ -15,7 +15,7 @@ void AddNode(Head** head, long data) {
   }
 
   node->data = data;
-  node->next_node = NULL;
+  node->next_node = nullptr;
 
   if ((*head) == NULL) {
     (*head) = malloc(sizeof(Head));
@@ -70,7 +70,7 @@ bool RemoveNode(Head** head, long data) {
   if (current_node == previous_node && current_node->next_node == NULL) {
     free(current_node);
     free((*head));
-    (*head) = NULL;
+    (*head) = nullptr;
 
     return true;
   }
@@ -139,11 +139,11 @@ void PrintList(Head** head) {
 
   while (current_node != NULL) {
     if (current_node->next_node == NULL) {
-      wprintf(L"%lc %d %lc %p %lc %lc NULL", kVerticalLine, current_node->data,
+      wprintf(L"%lc %ld %lc %p %lc %lc NULL", kVerticalLine, current_node->data,
               kVerticalLineDashed, current_node->next_node, kVerticalLine,
               kArrow);
     } else {
-      wprintf(L"%lc %d %lc %p %lc %lc ", kVerticalLine, current_node->data,
+      wprintf(L"%lc %ld %lc %p %lc %lc ", kVerticalLine, current_node->data,
               kVerticalLineDashed, current_node->next_node, kVerticalLine,
               kArrow);
     }
@@ -184,10 +184,10 @@ bool IsScanfInputValid(int input) {
 void PrintOperationFailedMessage() { printf("Operation failed.\n"); }
 
 int main() {
-  locale_t locale = newlocale(LC_CTYPE, "en_US", NULL);
+  locale_t locale = newlocale(LC_CTYPE, "en_US", nullptr);
   uselocale(locale);
 
-  Head* head = NULL;
+  Head* head = nullptr;
   char* option_id_input = malloc(sizeof(char));
   long option_id = -1;
   char* input_one_string = malloc(sizeof(char));
@@ -197,7 +197,7 @@ int main() {
 
   while (option_id != kQuit) {
     int number_of_assigned_input_items = 0;
-    char* end = NULL;
+    char* end = nullptr;
     long input_one_long = 0;
     long input_two_long = 0;
     bool success = false;
diff --git a/src/main.h b/src/main.h
index dd2d4fb..a49efda 100644
--- a/src/main.h
+++ b/src/main.h
@@ -1,9 +1,12 @@
+#ifndef MAIN_H
+#define MAIN_H
+
 #include <wchar.h>
 
-const wchar_t kVerticalLine = 0x2503;
-const wchar_t kVerticalLineDashed = 0x2506;
-const wchar_t kArrow = 0x2B95;
-const int kBase = 10;
+constexpr wchar_t kVerticalLine = 0x2503;
+constexpr wchar_t kVerticalLineDashed = 0x2506;
+constexpr wchar_t kArrow = 0x2B95;
+constexpr int kBase = 10;
 
 enum Commands { kAdd = 1, kRemove, kInsert, kPrint, kQuit };
 
@@ -22,3 +25,5 @@ struct Node {
   long data;
   Node* next_node;
 };
+
+#endif  // MAIN_H