diff --git a/drivers/base/iommu.c b/drivers/base/iommu.c
index 5e039d4f877c..c2d1eed90376 100644
--- a/drivers/base/iommu.c
+++ b/drivers/base/iommu.c
@@ -31,7 +31,7 @@ void register_iommu(struct iommu_ops *ops)
 	iommu_ops = ops;
 }
 
-bool iommu_found()
+bool iommu_found(void)
 {
 	return iommu_ops != NULL;
 }