diff --git a/include/llmr/geometry/sprite_atlas.hpp b/include/llmr/geometry/sprite_atlas.hpp
index 220edc701..13b85e548 100644
--- a/include/llmr/geometry/sprite_atlas.hpp
+++ b/include/llmr/geometry/sprite_atlas.hpp
@@ -62,7 +62,7 @@ private:
     BinPack<dimension> bin;
     std::map<std::string, Rect<dimension>> images;
     std::set<std::string> uninitialized;
-    char *data = nullptr;
+    uint32_t *data = nullptr;
     std::atomic<bool> dirty;
     uint32_t texture = 0;
     uint32_t filter = 0;
diff --git a/src/geometry/sprite_atlas.cpp b/src/geometry/sprite_atlas.cpp
index 35f6f4588..4404695f9 100644
--- a/src/geometry/sprite_atlas.cpp
+++ b/src/geometry/sprite_atlas.cpp
@@ -30,7 +30,7 @@ bool SpriteAtlas::resize(const float newRatio) {
     pixelRatio = newRatio;
 
     if (data) {
-        char *old_data = data;
+        uint32_t *old_data = data;
 
         data = nullptr;
         allocate();
@@ -185,7 +185,7 @@ void SpriteAtlas::allocate() {
     if (!data) {
         dimension w = static_cast<dimension>(width * pixelRatio);
         dimension h = static_cast<dimension>(height * pixelRatio);
-        data = (char *)calloc(w * h, sizeof(uint32_t));
+        data = (uint32_t *)calloc(w * h, sizeof(uint32_t));
     }
 }