diff --git a/demos/CUDA/BlackScholes/helper/helper_grad_verify.h b/demos/CUDA/BlackScholes/helper/helper_grad_verify.h
index 804079ce9..1b4ad8da1 100644
--- a/demos/CUDA/BlackScholes/helper/helper_grad_verify.h
+++ b/demos/CUDA/BlackScholes/helper/helper_grad_verify.h
@@ -12,7 +12,7 @@ const int OPT_SZ = OPT_N * sizeof(float);
 const float RISKFREE = 0.02f;
 const float VOLATILITY = 0.30f;
 
-#define DIV_UP(a, b) (((a) + (b)-1) / (b))
+#define DIV_UP(a, b) (((a) + (b) - 1) / (b))
 
 double d1(double S, double X, double T) {
   return (log(S / X) + (RISKFREE + 0.5 * VOLATILITY * VOLATILITY) * T) /