diff --git a/headers/enduro2d/base/main.hpp b/headers/enduro2d/base/main.hpp
index 3f1ec0f5..2cdf2acd 100644
--- a/headers/enduro2d/base/main.hpp
+++ b/headers/enduro2d/base/main.hpp
@@ -6,6 +6,4 @@
 
 #pragma once
 
-#include "types.hpp"
-
-e2d::i32 e2d_main(int argc, char *argv[]);
+int e2d_main(int argc, char *argv[]);
diff --git a/sources/enduro2d/core/render_impl/render_opengl.cpp b/sources/enduro2d/core/render_impl/render_opengl.cpp
index 2a1a57e0..3a4e4715 100644
--- a/sources/enduro2d/core/render_impl/render_opengl.cpp
+++ b/sources/enduro2d/core/render_impl/render_opengl.cpp
@@ -802,12 +802,12 @@ namespace e2d
         }
 
         bool need_color =
-            utils::enum_to_underlying(external_texture)
-            & utils::enum_to_underlying(render_target::external_texture::color);
+            !!(utils::enum_to_underlying(external_texture)
+            & utils::enum_to_underlying(render_target::external_texture::color));
 
         bool need_depth =
-            utils::enum_to_underlying(external_texture)
-            & utils::enum_to_underlying(render_target::external_texture::depth);
+            !!(utils::enum_to_underlying(external_texture)
+            & utils::enum_to_underlying(render_target::external_texture::depth));
 
         texture_ptr color;
         texture_ptr depth;
@@ -925,14 +925,14 @@ namespace e2d
         E2D_ASSERT(is_in_main_thread());
 
         bool clear_color =
-            utils::enum_to_underlying(command.clear_buffer())
-            & utils::enum_to_underlying(clear_command::buffer::color);
+            !!(utils::enum_to_underlying(command.clear_buffer())
+            & utils::enum_to_underlying(clear_command::buffer::color));
         bool clear_depth =
-            utils::enum_to_underlying(command.clear_buffer())
-            & utils::enum_to_underlying(clear_command::buffer::depth);
+            !!(utils::enum_to_underlying(command.clear_buffer())
+            & utils::enum_to_underlying(clear_command::buffer::depth));
         bool clear_stencil =
-            utils::enum_to_underlying(command.clear_buffer())
-            & utils::enum_to_underlying(clear_command::buffer::stencil);
+            !!(utils::enum_to_underlying(command.clear_buffer())
+            & utils::enum_to_underlying(clear_command::buffer::stencil));
 
         const render_target_ptr& rt = state_->render_target();
         bool has_color = !rt || rt->state().color() || !rt->state().color_rb().empty();
@@ -1012,9 +1012,9 @@ namespace e2d
             case pixel_declaration::pixel_type::depth16:
                 return true;
             case pixel_declaration::pixel_type::depth24:
-                return GLEW_OES_depth24;
+                return !!GLEW_OES_depth24;
             case pixel_declaration::pixel_type::depth32:
-                return GLEW_OES_depth32;
+                return !!GLEW_OES_depth32;
             case pixel_declaration::pixel_type::depth24_stencil8:
                 return GLEW_OES_packed_depth_stencil
                     || GLEW_EXT_packed_depth_stencil;
@@ -1039,10 +1039,10 @@ namespace e2d
             case pixel_declaration::pixel_type::rgb_pvrtc4:
             case pixel_declaration::pixel_type::rgba_pvrtc2:
             case pixel_declaration::pixel_type::rgba_pvrtc4:
-                return GLEW_IMG_texture_compression_pvrtc;
+                return !!GLEW_IMG_texture_compression_pvrtc;
             case pixel_declaration::pixel_type::rgba_pvrtc2_v2:
             case pixel_declaration::pixel_type::rgba_pvrtc4_v2:
-                return GLEW_IMG_texture_compression_pvrtc2;
+                return !!GLEW_IMG_texture_compression_pvrtc2;
             default:
                 E2D_ASSERT_MSG(false, "unexpected pixel type");
                 return false;
diff --git a/sources/enduro2d/core/vfs.cpp b/sources/enduro2d/core/vfs.cpp
index 5c2ed82c..69a75e1c 100644
--- a/sources/enduro2d/core/vfs.cpp
+++ b/sources/enduro2d/core/vfs.cpp
@@ -327,7 +327,7 @@ namespace e2d
             if ( mz_zip_reader_file_stat(state_->archive.get(), i, &file_stat) ) {
                 const str_view filename{file_stat.m_filename};
                 if ( filename.length() > parent.length() && filename.starts_with(parent) ) {
-                    func(file_stat.m_filename, file_stat.m_is_directory);
+                    func(file_stat.m_filename, !!file_stat.m_is_directory);
                 }
             }
         }
diff --git a/sources/enduro2d/core/window_impl/window_glfw.cpp b/sources/enduro2d/core/window_impl/window_glfw.cpp
index 3330b1d7..3c15cbe7 100644
--- a/sources/enduro2d/core/window_impl/window_glfw.cpp
+++ b/sources/enduro2d/core/window_impl/window_glfw.cpp
@@ -445,7 +445,7 @@ namespace e2d
             if ( self ) {
                 self->for_all_listeners(
                     &event_listener::on_window_focus,
-                    focused);
+                    !!focused);
             }
         }
 
@@ -454,7 +454,7 @@ namespace e2d
             if ( self ) {
                 self->for_all_listeners(
                     &event_listener::on_window_minimize,
-                    minimized);
+                    !!minimized);
             }
         }
     };