diff --git a/host/chez/lazy-bridge.ss b/host/chez/lazy-bridge.ss
index acd7dd9..76e0043 100644
--- a/host/chez/lazy-bridge.ss
+++ b/host/chez/lazy-bridge.ss
@@ -49,6 +49,13 @@
       (cseq-lazy x (lambda () (force-lazyseq coll)))
       (%ls-cons x coll))))
 
+;; (conj lazyseq x): conj onto a seq prepends, like any seq — (conj (rest xs) y).
+;; rest returns a lazyseq, so this is a common path; without it conj reports the
+;; lazyseq as an "unsupported collection".
+(define %ls-conj1 jolt-conj1)
+(set! jolt-conj1 (lambda (coll x)
+  (if (jolt-lazyseq? coll) (jolt-cons x coll) (%ls-conj1 coll x))))
+
 ;; A lazyseq is a NEW value type, so the dispatchers that DON'T route through
 ;; jolt-seq must learn it or a raw (unrealized) lazyseq escapes — e.g. the corpus
 ;; compares (= [1 3 5] (take-nth 2 …)) against the raw lazyseq, and jolt=2 would
diff --git a/host/chez/records.ss b/host/chez/records.ss
index 00b0a95..66fdc57 100644
--- a/host/chez/records.ss
+++ b/host/chez/records.ss
@@ -58,6 +58,14 @@
                  (find-method-any-protocol tag "valAt")
                  (find-method-any-protocol tag "cons"))))
        #t))
+;; a jrec that is map? — a record, or a deftype implementing clojure.lang
+;; .IPersistentMap (clojure.core.cache's caches do). `without` (dissoc) is the
+;; map-distinctive method: vectors/sets implement Associative/ILookup but not it.
+(define (jrec-maplike? x)
+  (and (jrec? x)
+       (or (jrec-record? x)
+           (find-method-any-protocol (jrec-tag x) "without"))
+       #t))
 (define jolt-deftype-kw (keyword "jolt" "deftype"))
 ;; unique present-vs-absent sentinel for extension-map lookups (so a present nil
 ;; in the extension map is distinguished from a genuine miss).
@@ -399,7 +407,7 @@
 ;; deftype is not. coll? additionally covers a deftype implementing a collection
 ;; interface. predicates.ss vars hold a snapshot, so re-def-var! after extending.
 (define %r-jolt-map? jolt-map?)
-(set! jolt-map? (lambda (x) (or (jrec-record? x) (%r-jolt-map? x))))
+(set! jolt-map? (lambda (x) (or (jrec-maplike? x) (%r-jolt-map? x))))
 (def-var! "clojure.core" "map?" jolt-map?)
 (def-var! "clojure.core" "coll?" (lambda (x) (or (jrec-collection? x) (jolt-coll-pred? x))))
 
diff --git a/host/chez/seq.ss b/host/chez/seq.ss
index 7ac020a..98401ad 100644
--- a/host/chez/seq.ss
+++ b/host/chez/seq.ss
@@ -161,6 +161,7 @@
   (cond
     ((procedure? f) (apply f args))
     ((keyword? f) (apply jolt-get (car args) f (cdr args)))   ; (:k m [d]) -> (get m :k [d])
+    ((jolt-symbol? f) (apply jolt-get (car args) f (cdr args)))   ; ('s m [d]) -> (get m 's [d])
     ((jolt-coll? f) (apply jolt-get f args))                  ; (coll k [d]) -> (get coll k [d])
     ((jolt-transient? f) (apply jolt-get f args))             ; a transient vec/map/set is callable on the JVM
     ;; a record/reify implementing clojure.lang.IFn is callable: dispatch to its
diff --git a/test/chez/corpus.edn b/test/chez/corpus.edn
index 0ea113d..c880e4b 100644
--- a/test/chez/corpus.edn
+++ b/test/chez/corpus.edn
@@ -3278,4 +3278,22 @@
   {:suite "interop / uri equality" :label "URIs are value-equal and usable as set members" :expected "[true true]" :actual "[(= (java.net.URI. \"/\") (java.net.URI. \"/\")) (= #{(java.net.URI. \"/\")} #{(java.net.URI. \"/\")})]"}
   {:suite "stdlib / clojure.walk" :label "macroexpand-all expands a form" :expected "true" :actual "(do (require (quote clojure.walk)) (seq? (clojure.walk/macroexpand-all (quote (when true 1)))))"}
   {:suite "regex / re-seq zero-width" :label "a zero-width match advances by one without repeating" :expected "[\"a\" \"\" \"a\" \"\"]" :actual "(vec (re-seq #\"a*\" \"aba\"))"}
+  {:suite "seqs / lazy-seq interop" :label "conj onto a rest-derived seq prepends" :expected "true" :actual "(= [9 2 3] (vec (conj (rest [1 2 3]) 9)))"}
+  {:suite "seqs / lazy-seq interop" :label "conj onto a lazy-seq prepends" :expected "true" :actual "(= [9 1 2] (vec (conj (lazy-seq (list 1 2)) 9)))"}
+  {:suite "seqs / lazy-seq interop" :label "into over a conj'd rest-seq" :expected "true" :actual "(= [0 2 3] (into [] (conj (rest [1 2 3]) 0)))"}
+  {:suite "seqs / lazy-seq interop" :label "first of a conj'd rest-seq" :expected "true" :actual "(= 9 (first (conj (rest [1 2 3]) 9)))"}
+  {:suite "seqs / lazy-seq interop" :label "count of a conj'd rest-seq" :expected "true" :actual "(= 3 (count (conj (rest [1 2 3]) 9)))"}
+  {:suite "seqs / lazy-seq interop" :label "nth into a rest-seq" :expected "true" :actual "(= 3 (nth (rest [1 2 3]) 1))"}
+  {:suite "seqs / lazy-seq interop" :label "reduce over a rest-seq" :expected "true" :actual "(= 5 (reduce + (rest [1 2 3])))"}
+  {:suite "seqs / lazy-seq interop" :label "a rest-seq equals the literal tail" :expected "true" :actual "(= (quote (2 3)) (rest [1 2 3]))"}
+  {:suite "seqs / lazy-seq interop" :label "map over a rest-seq" :expected "true" :actual "(= [3 4] (vec (map inc (rest [1 2 3]))))"}
+  {:suite "seqs / lazy-seq interop" :label "filter over a rest-seq" :expected "true" :actual "(= [3] (vec (filter odd? (rest [1 2 3 4]))))"}
+  {:suite "seqs / lazy-seq interop" :label "apply over a rest-seq" :expected "true" :actual "(= 5 (apply + (rest [1 2 3])))"}
+  {:suite "seqs / lazy-seq interop" :label "seq of an empty rest is nil" :expected "true" :actual "(nil? (seq (rest [1])))"}
+  {:suite "seqs / lazy-seq interop" :label "empty? of an empty rest" :expected "true" :actual "(empty? (rest [1]))"}
+  {:suite "seqs / lazy-seq interop" :label "cons onto a rest-seq" :expected "true" :actual "(= [0 2 3] (vec (cons 0 (rest [1 2 3]))))"}
+  {:suite "seqs / lazy-seq interop" :label "into a set from a rest-seq" :expected "true" :actual "(= #{2 3} (into #{} (rest [1 2 3])))"}
+  {:suite "ifn / symbol as fn" :label "a symbol invokes as a map lookup" :expected "true" :actual "(= 5 ('a {(quote a) 5}))"}
+  {:suite "ifn / symbol as fn" :label "a symbol fn takes a not-found default" :expected "true" :actual "(= :d ('a {} :d))"}
+  {:suite "ifn / symbol as fn" :label "a symbol works as a mapping fn" :expected "true" :actual "(= [1 2] (vec (map (quote k) [{(quote k) 1} {(quote k) 2}])))"}
 ]
diff --git a/test/chez/unit.edn b/test/chez/unit.edn
index cb1a1ec..5e85d49 100644
--- a/test/chez/unit.edn
+++ b/test/chez/unit.edn
@@ -563,4 +563,8 @@
   {:suite "bytes" :expr "(String. (byte-array [104 105]) \"UTF-8\")" :expected "hi"}
   {:suite "bytes" :expr "(int (first (String. (byte-array [200]) \"ISO-8859-1\")))" :expected "200"}
   {:suite "bytes" :expr "(String. (.getBytes \"round\" \"UTF-8\") \"UTF-8\")" :expected "round"}
+  {:suite "deftype-map" :expr "(do (deftype Mp [m] clojure.lang.IPersistentMap (without [_ k] m)) [(map? (->Mp 1)) (record? (->Mp 1))])" :expected "[true false]"}
+  {:suite "deftype-map" :expr "(do (deftype Op [s]) [(map? (->Op 1)) (record? (->Op 1)) (coll? (->Op 1))])" :expected "[false false false]"}
+  {:suite "deftype-map" :expr "(do (deftype Lc [xs] clojure.lang.Counted (count [_] (count xs)) clojure.lang.Seqable (seq [_] (seq xs))) [(coll? (->Lc [1 2])) (count (->Lc [1 2])) (vec (seq (->Lc [1 2])))])" :expected "[true 2 [1 2]]"}
+  {:suite "deftype-map" :expr "(do (defrecord Dr [a b]) [(map? (->Dr 1 2)) (record? (->Dr 1 2)) (coll? (->Dr 1 2))])" :expected "[true true true]"}
 ]