diff --git a/examples/main-GLFW_GLES2.cpp b/examples/main-GLFW_GLES2.cpp
index 913948427..e9c611fc1 100644
--- a/examples/main-GLFW_GLES2.cpp
+++ b/examples/main-GLFW_GLES2.cpp
@@ -58,7 +58,7 @@ int main()
     glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 2);
     glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);
 
-    GLFWwindow* window = glfwCreateWindow(800, 600, "TGUI example (GLFW-GLES2)", NULL, NULL);
+    GLFWwindow* window = glfwCreateWindow(800, 600, "TGUI example (GLFW-GLES2)", nullptr, nullptr);
     glfwMakeContextCurrent(window);
 
     glfwSwapInterval(1);
diff --git a/examples/main-GLFW_OPENGL3.cpp b/examples/main-GLFW_OPENGL3.cpp
index dcf35f844..801bf1402 100644
--- a/examples/main-GLFW_OPENGL3.cpp
+++ b/examples/main-GLFW_OPENGL3.cpp
@@ -59,7 +59,7 @@ int main()
     glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
     glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GLFW_TRUE); // Required for macOS
 
-    GLFWwindow* window = glfwCreateWindow(800, 600, "TGUI example (GLFW-OpenGL3)", NULL, NULL);
+    GLFWwindow* window = glfwCreateWindow(800, 600, "TGUI example (GLFW-OpenGL3)", nullptr, nullptr);
     glfwMakeContextCurrent(window);
 
     glfwSwapInterval(1);
diff --git a/include/TGUI/Backend/Window/Backend.hpp b/include/TGUI/Backend/Window/Backend.hpp
index 5084df1f3..522516f2f 100644
--- a/include/TGUI/Backend/Window/Backend.hpp
+++ b/include/TGUI/Backend/Window/Backend.hpp
@@ -53,7 +53,7 @@ namespace tgui
     /// @brief Checks whether the backend differs from a nullptr
     /// @return Has setBackend been called with a valid backend?
     ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
-    TGUI_API bool isBackendSet();
+    [[nodiscard]] TGUI_API bool isBackendSet();
 
     ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
     /// @brief Changes the global backend
diff --git a/include/TGUI/Config.hpp.in b/include/TGUI/Config.hpp.in
index e9f328b3a..117301425 100644
--- a/include/TGUI/Config.hpp.in
+++ b/include/TGUI/Config.hpp.in
@@ -131,7 +131,7 @@
 // Include the version header when C++20 is available to use the library feature-testing macros
 #if TGUI_COMPILED_WITH_CPP_VER >= 20
     #include <version>
-#elif defined(__has_include)
+#else
     // Try including the header even when TGUI itself wasn't compiled with C++20
     #if __has_include(<version>)
         #include <version>
diff --git a/include/TGUI/Global.hpp b/include/TGUI/Global.hpp
index b435be80c..a3be3770f 100644
--- a/include/TGUI/Global.hpp
+++ b/include/TGUI/Global.hpp
@@ -84,7 +84,7 @@ namespace tgui
     ///
     /// @since TGUI 1.13
     ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
-    TGUI_API bool getTextInputUsesTextCursorByDefault();
+    [[nodiscard]] TGUI_API bool getTextInputUsesTextCursorByDefault();
 
     ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
     /// @brief Sets the default text size for all widgets created after calling the function
diff --git a/src/DefaultBackendWindow.cpp b/src/DefaultBackendWindow.cpp
index 949c3ae4f..46e90dd1b 100644
--- a/src/DefaultBackendWindow.cpp
+++ b/src/DefaultBackendWindow.cpp
@@ -64,7 +64,6 @@
 namespace tgui
 {
 #if TGUI_HAS_BACKEND_SFML_GRAPHICS || TGUI_HAS_BACKEND_SFML_OPENGL3
-
     class BackendWindowSFML : public DefaultBackendWindow
     {
     public:
@@ -383,7 +382,6 @@ namespace tgui
     };
 
 #elif TGUI_HAS_BACKEND_GLFW_OPENGL3 || TGUI_HAS_BACKEND_GLFW_GLES2
-
     class BackendWindowGLFW : public DefaultBackendWindow
     {
     public:
@@ -568,7 +566,6 @@ namespace tgui
     };
 
 #elif TGUI_HAS_BACKEND_RAYLIB
-
     class BackendWindowRaylib : public DefaultBackendWindow
     {
     public:
@@ -634,8 +631,8 @@ namespace tgui
                         event.type = Event::Type::Closed;
                         return true;
                     }
-                    else // This is the second attempt to close the window (this should not happen), just close it
-                        close();
+                    // This is the second attempt to close the window (this should not happen), just close it
+                    close();
                 }
             }
 
diff --git a/src/FileDialogIconLoaderLinux.cpp b/src/FileDialogIconLoaderLinux.cpp
index 8ee858cb8..1d5aafa1c 100644
--- a/src/FileDialogIconLoaderLinux.cpp
+++ b/src/FileDialogIconLoaderLinux.cpp
@@ -33,11 +33,9 @@
     #include <fstream>
     #include <thread>
 
-    #if defined(__has_include)
-        #if __has_include(<magic.h>)
-            #define TGUI_MAGIC_HEADER_INCLUDED
-            #include <magic.h>
-        #endif
+    #if __has_include(<magic.h>)
+        #define TGUI_MAGIC_HEADER_INCLUDED
+        #include <magic.h>
     #endif
 
     #if !defined(TGUI_MAGIC_HEADER_INCLUDED)
diff --git a/src/FileDialogIconLoaderWindows.cpp b/src/FileDialogIconLoaderWindows.cpp
index 7c46b192d..4b5c861d6 100644
--- a/src/FileDialogIconLoaderWindows.cpp
+++ b/src/FileDialogIconLoaderWindows.cpp
@@ -28,15 +28,13 @@
 
     #include <TGUI/extlibs/IncludeWindows.hpp>
 
-    #if defined(__has_include)
-        #if __has_include(<shellapi.h>)
-            #define TGUI_SHELL_API_HEADER_INCLUDED
-            #include <shellapi.h>
-
-            // MinGW.org based TDM-GCC doesn't define SHGFI_ADDOVERLAYS
-            #ifndef SHGFI_ADDOVERLAYS
-                #define SHGFI_ADDOVERLAYS 0x000000020
-            #endif
+    #if __has_include(<shellapi.h>)
+        #define TGUI_SHELL_API_HEADER_INCLUDED
+        #include <shellapi.h>
+
+        // MinGW.org based TDM-GCC doesn't define SHGFI_ADDOVERLAYS
+        #ifndef SHGFI_ADDOVERLAYS
+            #define SHGFI_ADDOVERLAYS 0x000000020
         #endif
     #endif