diff --git a/hw/spapr_iommu.c b/hw/spapr_iommu.c
index 02d78cc..3011b25 100644
--- a/hw/spapr_iommu.c
+++ b/hw/spapr_iommu.c
@@ -120,6 +120,12 @@ DMAContext *spapr_tce_new_dma_context(uint32_t liobn, size_t window_size)
 {
     sPAPRTCETable *tcet;
 
+    if (spapr_tce_find_by_liobn(liobn)) {
+        fprintf(stderr, "Attempted to create TCE table with duplicate"
+                " LIOBN 0x%x\n", liobn);
+        return NULL;
+    }
+
     if (!window_size) {
         return NULL;
     }