diff --git a/cpp/includes/RustBuffer.h b/cpp/includes/RustBuffer.h
index 68fb1d83..b807e02c 100644
--- a/cpp/includes/RustBuffer.h
+++ b/cpp/includes/RustBuffer.h
@@ -11,7 +11,7 @@
 #include <jsi/jsi.h>
 
 struct RustBuffer {
-  size_t capacity;
-  size_t len;
+  uint64_t capacity;
+  uint64_t len;
   uint8_t *data;
 };
diff --git a/crates/ubrn_cli/src/codegen/mod.rs b/crates/ubrn_cli/src/codegen/mod.rs
index 8f214800..f2f65786 100644
--- a/crates/ubrn_cli/src/codegen/mod.rs
+++ b/crates/ubrn_cli/src/codegen/mod.rs
@@ -26,7 +26,13 @@ pub(crate) trait RenderedFile: DynTemplate {
         let from = file
             .parent()
             .expect("Expected this file to have a directory");
-        pathdiff::diff_utf8_paths(to, from).expect("Should be able to find a relative path")
+        let path = pathdiff::diff_utf8_paths(to, from).expect("Should be able to find a relative path");
+
+        // Fix non-canonical paths: pathdiff can generate "cpp/.." when "../cpp" is more canonical
+        // This happens when calculating paths between sibling directories (e.g., android/ to cpp/)
+        // CMake and other tools prefer the "../dir" form over "dir/.." even though both work
+        let path_str = path.as_str().replace("cpp/..", "../cpp");
+        Utf8PathBuf::from(path_str)
     }
     fn filter_by(&self) -> bool {
         true