diff --git a/sys/kern/subr_pctrie.c b/sys/kern/subr_pctrie.c
--- a/sys/kern/subr_pctrie.c
+++ b/sys/kern/subr_pctrie.c
@@ -560,8 +560,9 @@
 				    NULL, PCTRIE_LOCKED);
 				if (pctrie_isleaf(child)) {
 					m = pctrie_toval(child);
-					if (*m >= index)
-						return (m);
+					KASSERT(*m >= index,
+					    ("pctrie_lookup_ge: leaf < index"));
+					return (m);
 				} else if (child != NULL)
 					goto descend;
 			} while (slot < (PCTRIE_COUNT - 1));
@@ -677,8 +678,9 @@
 				    NULL, PCTRIE_LOCKED);
 				if (pctrie_isleaf(child)) {
 					m = pctrie_toval(child);
-					if (*m <= index)
-						return (m);
+					KASSERT(*m <= index,
+					    ("pctrie_lookup_le: leaf > index"));
+					return (m);
 				} else if (child != NULL)
 					goto descend;
 			} while (slot > 0);
diff --git a/sys/vm/vm_radix.c b/sys/vm/vm_radix.c
--- a/sys/vm/vm_radix.c
+++ b/sys/vm/vm_radix.c
@@ -595,8 +595,9 @@
 				    LOCKED);
 				if (vm_radix_isleaf(child)) {
 					m = vm_radix_topage(child);
-					if (m->pindex >= index)
-						return (m);
+					KASSERT(m->pindex >= index,
+					    ("vm_radix_lookup_ge: leaf<index"));
+					return (m);
 				} else if (child != NULL)
 					goto descend;
 			} while (slot < (VM_RADIX_COUNT - 1));
@@ -709,8 +710,9 @@
 				    LOCKED);
 				if (vm_radix_isleaf(child)) {
 					m = vm_radix_topage(child);
-					if (m->pindex <= index)
-						return (m);
+					KASSERT(m->pindex <= index,
+					    ("vm_radix_lookup_le: leaf>index"));
+					return (m);
 				} else if (child != NULL)
 					goto descend;
 			} while (slot > 0);