diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index ee06993675..609b80750a 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -948,6 +948,7 @@ static VTDBus *vtd_find_as_from_bus_num(IntelIOMMUState *s, uint8_t bus_num)
                 return vtd_bus;
             }
         }
+        vtd_bus = NULL;
     }
     return vtd_bus;
 }