diff --git a/sys/x86/x86/busdma_machdep.c b/sys/x86/x86/busdma_machdep.c
index 3dade64692d6..168645702bc5 100644
--- a/sys/x86/x86/busdma_machdep.c
+++ b/sys/x86/x86/busdma_machdep.c
@@ -300,6 +300,10 @@ bus_dma_tag_destroy(bus_dma_tag_t dmat)
 }
 
 #ifndef ACPI_DMAR
+bool bus_dma_iommu_set_buswide(device_t dev);
+int bus_dma_iommu_load_ident(bus_dma_tag_t dmat, bus_dmamap_t map,   
+    vm_paddr_t start, vm_size_t length, int flags);
+
 bool
 bus_dma_iommu_set_buswide(device_t dev)
 {