diff --git a/include/jemalloc/internal/emap.h b/include/jemalloc/internal/emap.h
index 3e397483..afb4983c 100644
--- a/include/jemalloc/internal/emap.h
+++ b/include/jemalloc/internal/emap.h
@@ -139,6 +139,9 @@ emap_assert_not_mapped(tsdn_t *tsdn, emap_t *emap, edata_t *edata) {
 static inline void
 emap_update_rtree_at_addr(tsdn_t *tsdn, rtree_t *rtree, edata_t *expected_edata,
     uintptr_t addr, extent_state_t state) {
+	witness_assert_positive_depth_to_rank(tsdn_witness_tsdp_get(tsdn),
+	    WITNESS_RANK_CORE);
+
 	rtree_ctx_t rtree_ctx_fallback;
 	rtree_ctx_t *rtree_ctx = tsdn_rtree_ctx(tsdn, &rtree_ctx_fallback);
 
diff --git a/include/jemalloc/internal/witness.h b/include/jemalloc/internal/witness.h
index 66dcf664..4cebb6e1 100644
--- a/include/jemalloc/internal/witness.h
+++ b/include/jemalloc/internal/witness.h
@@ -243,26 +243,13 @@ witness_assert_not_owner(witness_tsdn_t *witness_tsdn,
 	}
 }
 
-static inline void
-witness_assert_depth_to_rank(witness_tsdn_t *witness_tsdn,
-    witness_rank_t rank_inclusive, unsigned depth) {
-	witness_tsd_t *witness_tsd;
-	unsigned d;
-	witness_list_t *witnesses;
-	witness_t *w;
+/* Returns depth.  Not intended for direct use. */
+static inline unsigned
+witness_depth_to_rank(witness_list_t *witnesses, witness_rank_t rank_inclusive)
+{
+	unsigned d = 0;
+	witness_t *w = ql_last(witnesses, link);
 
-	if (!config_debug) {
-		return;
-	}
-
-	if (witness_tsdn_null(witness_tsdn)) {
-		return;
-	}
-	witness_tsd = witness_tsdn_tsd(witness_tsdn);
-
-	d = 0;
-	witnesses = &witness_tsd->witnesses;
-	w = ql_last(witnesses, link);
 	if (w != NULL) {
 		ql_reverse_foreach(w, witnesses, link) {
 			if (w->rank < rank_inclusive) {
@@ -271,6 +258,20 @@ witness_assert_depth_to_rank(witness_tsdn_t *witness_tsdn,
 			d++;
 		}
 	}
+
+	return d;
+}
+
+static inline void
+witness_assert_depth_to_rank(witness_tsdn_t *witness_tsdn,
+    witness_rank_t rank_inclusive, unsigned depth) {
+	if (!config_debug || witness_tsdn_null(witness_tsdn)) {
+		return;
+	}
+
+	witness_list_t *witnesses = &witness_tsdn_tsd(witness_tsdn)->witnesses;
+	unsigned d = witness_depth_to_rank(witnesses, rank_inclusive);
+
 	if (d != depth) {
 		witness_depth_error(witnesses, rank_inclusive, depth);
 	}
@@ -286,6 +287,21 @@ witness_assert_lockless(witness_tsdn_t *witness_tsdn) {
 	witness_assert_depth(witness_tsdn, 0);
 }
 
+static inline void
+witness_assert_positive_depth_to_rank(witness_tsdn_t *witness_tsdn,
+    witness_rank_t rank_inclusive) {
+	if (!config_debug || witness_tsdn_null(witness_tsdn)) {
+		return;
+	}
+
+	witness_list_t *witnesses = &witness_tsdn_tsd(witness_tsdn)->witnesses;
+	unsigned d = witness_depth_to_rank(witnesses, rank_inclusive);
+
+	if (d == 0) {
+		witness_depth_error(witnesses, rank_inclusive, 1);
+	}
+}
+
 static inline void
 witness_lock(witness_tsdn_t *witness_tsdn, witness_t *witness) {
 	witness_tsd_t *witness_tsd;