diff --git a/src/engine/renderer/opengl/renderer_opengl.cc b/src/engine/renderer/opengl/renderer_opengl.cc
index 9693f2b..0d0801e 100644
--- a/src/engine/renderer/opengl/renderer_opengl.cc
+++ b/src/engine/renderer/opengl/renderer_opengl.cc
@@ -185,8 +185,8 @@ void RendererOpenGL::DestroyGeometry(uint64_t resource_id) {
 }
 
 void RendererOpenGL::Draw(uint64_t resource_id,
-                          uint64_t num_indices,
-                          uint64_t start_offset) {
+                          size_t num_indices,
+                          size_t start_offset) {
   auto it = geometries_.find(resource_id);
   if (it == geometries_.end())
     return;
@@ -321,7 +321,7 @@ void RendererOpenGL::DestroyTexture(uint64_t resource_id) {
 }
 
 void RendererOpenGL::ActivateTexture(uint64_t resource_id,
-                                     uint64_t texture_unit) {
+                                     size_t texture_unit) {
   if (texture_unit >= kMaxTextureUnits) {
     DLOG(0) << "Invalid texture unit " << texture_unit;
     return;
diff --git a/src/engine/renderer/opengl/renderer_opengl.h b/src/engine/renderer/opengl/renderer_opengl.h
index 8d2ee61..e4658cb 100644
--- a/src/engine/renderer/opengl/renderer_opengl.h
+++ b/src/engine/renderer/opengl/renderer_opengl.h
@@ -50,8 +50,8 @@ class RendererOpenGL final : public Renderer {
 
   void DestroyGeometry(uint64_t resource_id) final;
   void Draw(uint64_t resource_id,
-            uint64_t num_indices = 0,
-            uint64_t start_offset = 0) final;
+            size_t num_indices = 0,
+            size_t start_offset = 0) final;
 
   uint64_t CreateTexture() final;
   void UpdateTexture(uint64_t resource_id, std::unique_ptr<Image> image) final;
@@ -62,7 +62,7 @@ class RendererOpenGL final : public Renderer {
                      size_t data_size,
                      uint8_t* image_data) final;
   void DestroyTexture(uint64_t resource_id) final;
-  void ActivateTexture(uint64_t resource_id, uint64_t texture_unit) final;
+  void ActivateTexture(uint64_t resource_id, size_t texture_unit) final;
 
   uint64_t CreateShader(std::unique_ptr<ShaderSource> source,
                         const VertexDescription& vertex_description,
diff --git a/src/engine/renderer/renderer.h b/src/engine/renderer/renderer.h
index 3959219..010c572 100644
--- a/src/engine/renderer/renderer.h
+++ b/src/engine/renderer/renderer.h
@@ -57,8 +57,8 @@ class Renderer {
                               const void* indices) = 0;
   virtual void DestroyGeometry(uint64_t resource_id) = 0;
   virtual void Draw(uint64_t resource_id,
-                    uint64_t num_indices = 0,
-                    uint64_t start_offset = 0) = 0;
+                    size_t num_indices = 0,
+                    size_t start_offset = 0) = 0;
 
   virtual uint64_t CreateTexture() = 0;
   virtual void UpdateTexture(uint64_t resource_id,
@@ -70,7 +70,7 @@ class Renderer {
                              size_t data_size,
                              uint8_t* image_data) = 0;
   virtual void DestroyTexture(uint64_t resource_id) = 0;
-  virtual void ActivateTexture(uint64_t resource_id, uint64_t texture_unit) = 0;
+  virtual void ActivateTexture(uint64_t resource_id, size_t texture_unit) = 0;
 
   virtual uint64_t CreateShader(std::unique_ptr<ShaderSource> source,
                                 const VertexDescription& vertex_description,
diff --git a/src/engine/renderer/vulkan/renderer_vulkan.cc b/src/engine/renderer/vulkan/renderer_vulkan.cc
index 4d3922f..adda543 100644
--- a/src/engine/renderer/vulkan/renderer_vulkan.cc
+++ b/src/engine/renderer/vulkan/renderer_vulkan.cc
@@ -525,8 +525,8 @@ void RendererVulkan::DestroyGeometry(uint64_t resource_id) {
 }
 
 void RendererVulkan::Draw(uint64_t resource_id,
-                          uint64_t num_indices,
-                          uint64_t start_offset) {
+                          size_t num_indices,
+                          size_t start_offset) {
   auto it = geometries_.find(resource_id);
   if (it == geometries_.end())
     return;
@@ -629,7 +629,7 @@ void RendererVulkan::DestroyTexture(uint64_t resource_id) {
 }
 
 void RendererVulkan::ActivateTexture(uint64_t resource_id,
-                                     uint64_t texture_unit) {
+                                     size_t texture_unit) {
   auto it = textures_.find(resource_id);
   if (it == textures_.end())
     return;
diff --git a/src/engine/renderer/vulkan/renderer_vulkan.h b/src/engine/renderer/vulkan/renderer_vulkan.h
index 40bd713..1eb7475 100644
--- a/src/engine/renderer/vulkan/renderer_vulkan.h
+++ b/src/engine/renderer/vulkan/renderer_vulkan.h
@@ -50,8 +50,8 @@ class RendererVulkan final : public Renderer {
                       const void* indices) final;
   void DestroyGeometry(uint64_t resource_id) final;
   void Draw(uint64_t resource_id,
-            uint64_t num_indices = 0,
-            uint64_t start_offset = 0) final;
+            size_t num_indices = 0,
+            size_t start_offset = 0) final;
 
   uint64_t CreateTexture() final;
   void UpdateTexture(uint64_t resource_id, std::unique_ptr<Image> image) final;
@@ -62,7 +62,7 @@ class RendererVulkan final : public Renderer {
                      size_t data_size,
                      uint8_t* image_data) final;
   void DestroyTexture(uint64_t resource_id) final;
-  void ActivateTexture(uint64_t resource_id, uint64_t texture_unit) final;
+  void ActivateTexture(uint64_t resource_id, size_t texture_unit) final;
 
   uint64_t CreateShader(std::unique_ptr<ShaderSource> source,
                         const VertexDescription& vertex_description,