diff --git a/fastsafetensors/cpp/ext.hpp b/fastsafetensors/cpp/ext.hpp
index 961011f..770d3a1 100644
--- a/fastsafetensors/cpp/ext.hpp
+++ b/fastsafetensors/cpp/ext.hpp
@@ -39,7 +39,12 @@ typedef struct CUfileError { CUfileOpError err; } CUfileError_t;
 // Define minimal CUDA/HIP types for both platforms to avoid compile-time dependencies
 // We load all GPU functions dynamically at runtime via dlopen()
 typedef enum cudaError { cudaSuccess = 0, cudaErrorMemoryAllocation = 2 } cudaError_t;
+// Platform-specific enum values - CUDA and HIP have different values for HostToDevice
+#ifdef USE_ROCM
+enum cudaMemcpyKind { cudaMemcpyHostToDevice=1, cudaMemcpyDefault = 4 };
+#else
 enum cudaMemcpyKind { cudaMemcpyHostToDevice=2, cudaMemcpyDefault = 4 };
+#endif
 
 
 typedef enum CUfileFeatureFlags {