diff --git a/pystencils/backends/opencl_backend.py b/pystencils/backends/opencl_backend.py
index 9fe7b9788689f0d191ef0c6da5137bde9ef8c66a..be9d6adb35654301af0c18a4491c2fc3fe93dce6 100644
--- a/pystencils/backends/opencl_backend.py
+++ b/pystencils/backends/opencl_backend.py
@@ -83,7 +83,7 @@ class OpenClSympyPrinter(CudaSympyPrinter):
         function_name, dimension = tuple(symbol_name.split("."))
         dimension = self.DIMENSION_MAPPING[dimension]
         function_name = self.INDEXING_FUNCTION_MAPPING[function_name]
-        return f"(int) {function_name}({dimension})"
+        return f"(int64_t) {function_name}({dimension})"
 
     def _print_TextureAccess(self, node):
         raise NotImplementedError()