diff --git a/Tests/CudaOnly/OptixIR/main.cu b/Tests/CudaOnly/OptixIR/main.cu
index c79829b297..1238cbecaa 100644
--- a/Tests/CudaOnly/OptixIR/main.cu
+++ b/Tests/CudaOnly/OptixIR/main.cu
@@ -1,3 +1,4 @@
+#include <cstdint>
 #include <fstream>
 #include <iostream>
 #include <string>