diff --git a/src/shader.c b/src/shader.c
index ec6f5f2..ef5e2c3 100644
--- a/src/shader.c
+++ b/src/shader.c
@@ -67,11 +67,12 @@ wn_shader *wn_shader_init(Arena *arena,
   shader->shaderProgram = shaderProgram;
   shader->success = true;
 
-  arena_deinit_task_push(arena, (void *)shader, *wn_shader_deinit);
+  arena_deinit_task_push(arena, (void *)shader,
+                         (void (*)(void *))wn_shader_deinit);
   return shader;
 }
 
-void wn_shader_deinit(void *shader) {
+void wn_shader_deinit(wn_shader *shader) {
   wn_shader *cast_shader = (wn_shader *)shader;
   glDeleteProgram(cast_shader->shaderProgram);
 }
diff --git a/src/shader.h b/src/shader.h
index 318974c..7f7a4e8 100644
--- a/src/shader.h
+++ b/src/shader.h
@@ -17,4 +17,4 @@ typedef struct wn_shader_s wn_shader;
 wn_shader *wn_shader_init(Arena *arena,
                           wn_shader_code_location shader_code_location);
 
-void wn_shader_deinit(void* shader);
+void wn_shader_deinit(wn_shader *shader);
diff --git a/src/window.c b/src/window.c
index e652734..641209d 100644
--- a/src/window.c
+++ b/src/window.c
@@ -56,12 +56,13 @@ wn_window *wn_window_init(Arena *arena) {
   SDL_SetWindowRelativeMouseMode(window->window, true);
   SDL_GetRelativeMouseState(NULL, NULL);
 
-  arena_deinit_task_push(arena, (void *)window, *wn_window_deinit);
+  arena_deinit_task_push(arena, (void *)window,
+                         (void (*)(void *))wn_window_deinit);
 
   return window;
 }
 
-void wn_window_deinit(void *window) {
+void wn_window_deinit(wn_window *window) {
   wn_window *cast_window = (wn_window *)window;
   SDL_GL_DestroyContext(cast_window->glcontext);
   SDL_DestroyWindow(cast_window->window);
diff --git a/src/window.h b/src/window.h
index a62c07c..7603328 100644
--- a/src/window.h
+++ b/src/window.h
@@ -15,6 +15,6 @@ struct wn_window_s {
 typedef struct wn_window_s wn_window;
 
 wn_window *wn_window_init(Arena *arena);
-void wn_window_deinit(void *window);
+void wn_window_deinit(wn_window *window);
 
 void wn_swapwindow(wn_window *window);