diff --git a/nvml.cpp b/nvml.cpp
index 9b1334e..553940b 100644
--- a/nvml.cpp
+++ b/nvml.cpp
@@ -25,6 +25,9 @@
 #include "miner.h"
 #include "cuda_runtime.h"
 
+// cuda.cpp
+int cuda_num_devices();
+
 #ifdef USE_WRAPNVML
 
 #include "nvml.h"