diff --git a/.beads/issues.jsonl b/.beads/issues.jsonl
index 72c32ce..169cb18 100644
--- a/.beads/issues.jsonl
+++ b/.beads/issues.jsonl
@@ -5,6 +5,7 @@
 {"_type":"issue","id":"jolt-x8s","title":"CRITICAL: collections not callable as IFn (vector/map/set)","status":"closed","priority":1,"issue_type":"bug","owner":"yogthos@gmail.com","created_at":"2026-06-04T17:46:14Z","created_by":"Yogthos","updated_at":"2026-06-04T17:50:54Z","closed_at":"2026-06-04T17:50:54Z","dependency_count":0,"dependent_count":0,"comment_count":0}
 {"_type":"issue","id":"jolt-alz","title":"CRITICAL: self-referential lazy-seq/lazy-cat yields only literal prefix","status":"closed","priority":1,"issue_type":"bug","owner":"yogthos@gmail.com","created_at":"2026-06-04T17:46:13Z","created_by":"Yogthos","updated_at":"2026-06-04T18:09:15Z","closed_at":"2026-06-04T18:09:15Z","dependency_count":0,"dependent_count":0,"comment_count":0}
 {"_type":"issue","id":"jolt-wec","title":"CRITICAL: multi-collection map returns unrealized thunk","status":"closed","priority":1,"issue_type":"bug","owner":"yogthos@gmail.com","created_at":"2026-06-04T17:46:12Z","created_by":"Yogthos","updated_at":"2026-06-04T18:06:02Z","closed_at":"2026-06-04T18:06:02Z","dependency_count":0,"dependent_count":0,"comment_count":0}
+{"_type":"issue","id":"jolt-lko","title":"clojure-test-suite: strictness — throw on malformed calls like Clojure","description":"Make jolt throw where Clojure throws (bad-shape conj!/assoc!, arithmetic on non-numbers, out-of-range indices, etc.) to satisfy the suite's ~292 p/thrown? assertions. Targeted input validation across affected fns; guard against regressing jolt's spec/conformance.","status":"in_progress","priority":2,"issue_type":"task","assignee":"Yogthos","owner":"yogthos@gmail.com","created_at":"2026-06-05T14:45:20Z","created_by":"Yogthos","updated_at":"2026-06-05T14:45:39Z","started_at":"2026-06-05T14:45:39Z","dependency_count":0,"dependent_count":0,"comment_count":0}
 {"_type":"issue","id":"jolt-kxb","title":"clojure-test-suite: transducers don't short-circuit over infinite seqs (hangs)","description":"(into [] (take 5) (range)) and similar transducer-over-infinite forms hang jolt's eager evaluator (no reduced/early-termination). 7 suite files time out. Make transducing honor reduced.","status":"closed","priority":2,"issue_type":"bug","assignee":"Yogthos","owner":"yogthos@gmail.com","created_at":"2026-06-05T13:05:18Z","created_by":"Yogthos","updated_at":"2026-06-05T13:18:37Z","started_at":"2026-06-05T13:09:59Z","closed_at":"2026-06-05T13:18:37Z","close_reason":"reduce-with-reduced steps lazy seqs incrementally; transducers short-circuit over infinite seqs","dependency_count":0,"dependent_count":0,"comment_count":0}
 {"_type":"issue","id":"jolt-js6","title":"Port clojure-test-suite as integration battery","description":"Build a minimal clojure.test + portability shim so Jolt can load the external ~/src/clojure-test-suite (240 per-fn .cljc files in clojure.test format). Add a baseline-guarded integration runner following the jank-conformance pattern (skip if absent).","status":"closed","priority":2,"issue_type":"task","assignee":"Yogthos","owner":"yogthos@gmail.com","created_at":"2026-06-05T12:22:01Z","created_by":"Yogthos","updated_at":"2026-06-05T13:05:04Z","started_at":"2026-06-05T12:22:14Z","closed_at":"2026-06-05T13:05:04Z","close_reason":"Ported clojure-test-suite as baseline-guarded integration battery; surfaced+fixed 2 evaluator macro bugs","dependency_count":0,"dependent_count":0,"comment_count":0}
 {"_type":"issue","id":"jolt-i3g","title":"Clear final 2 SCI bootstrap forms (Var/IVar collision + clojure.repl/template)","description":"namespaces.cljc forms 126/127 fail: (126) lang_stubs IVar collides with real vars.cljc IVar so unbind dispatch misses on sci.lang.Var; (127) clojure.repl + clojure.template namespaces missing. Fix: trim bootstrap stubs to let real modules own canonical protocols/types; port clojure.repl + clojure.template.","status":"closed","priority":2,"issue_type":"task","owner":"yogthos@gmail.com","created_at":"2026-06-05T03:21:40Z","created_by":"Yogthos","updated_at":"2026-06-05T03:35:43Z","closed_at":"2026-06-05T03:35:43Z","close_reason":"Done — SCI bootstrap now loads 422/422 with 0 failures. Fixed deftype protocol-method registration, with-meta on functions, select-keys over vectors, require :as+:refer, defmethod-on-fn; added clojure.set/join and host-module stubs. test-load-sci asserts 0 failures.","dependency_count":0,"dependent_count":0,"comment_count":0}
diff --git a/src/jolt/core.janet b/src/jolt/core.janet
index cfb25a2..ca6fab6 100644
--- a/src/jolt/core.janet
+++ b/src/jolt/core.janet
@@ -122,11 +122,20 @@
 (defn core-false? [x] (= false x))
 (defn core-identical? [a b] (= a b))
 
-(defn core-zero? [x] (and (number? x) (= x 0)))
-(defn core-pos? [x] (and (number? x) (> x 0)))
-(defn core-neg? [x] (and (number? x) (< x 0)))
-(defn core-even? [n] (= 0 (% n 2)))
-(defn core-odd? [n] (not= 0 (% n 2)))
+# Strictness helpers: like Clojure, numeric ops reject non-numbers, and the
+# integer ops (odd?/even?) reject non-integers (incl. infinities, NaN, fractions).
+(defn- finite-num? [x] (and (number? x) (= x x) (< (if (< x 0) (- x) x) math/inf)))
+(defn- need-num [x op]
+  (if (number? x) x (error (string op " requires a number, got " (type x)))))
+(defn- need-int [x op]
+  (if (and (number? x) (= x x) (< (if (< x 0) (- x) x) math/inf) (= x (math/floor x))) x
+    (error (string op " requires an integer"))))
+
+(defn core-zero? [x] (= (need-num x "zero?") 0))
+(defn core-pos? [x] (> (need-num x "pos?") 0))
+(defn core-neg? [x] (< (need-num x "neg?") 0))
+(defn core-even? [n] (= 0 (% (need-int n "even?") 2)))
+(defn core-odd? [n] (not= 0 (% (need-int n "odd?") 2)))
 
 (defn core-integer? [x] (and (number? x) (= x (math/floor x))))
 (defn core-boolean? [x] (or (= x true) (= x false)))
@@ -173,14 +182,17 @@
 (def core-dec dec)
 # Clojure integer division: quot truncates toward zero; rem matches the sign of
 # the dividend; mod matches the sign of the divisor (floored).
-(def core-quot (fn [n d] (let [q (/ n d)] (if (< q 0) (math/ceil q) (math/floor q)))))
+(def core-quot (fn [n d]
+  (when (or (not (finite-num? n)) (not (finite-num? d))) (error "quot requires finite numbers"))
+  (when (= d 0) (error "Divide by zero"))
+  (let [q (/ n d)] (if (< q 0) (math/ceil q) (math/floor q)))))
 (def core-rem (fn [n d] (- n (* (core-quot n d) d))))
 (def core-mod (fn [n d]
   (let [m (core-rem n d)]
     (if (or (= m 0) (= (> n 0) (> d 0))) m (+ m d)))))
 
-(defn core-max [& args] (apply max args))
-(defn core-min [& args] (apply min args))
+(defn core-max [& args] (each x args (need-num x "max")) (apply max args))
+(defn core-min [& args] (each x args (need-num x "min")) (apply min args))
 
 (defn core-abs [x] (if (neg? x) (- 0 x) x))
 (defn core-rand [] (math/random))
@@ -268,16 +280,18 @@
 (defn core-not= [& args] (not (apply core-= args)))
 
 # Comparisons are variadic: (< a b c) means a < b < c.
-(defn- chain-cmp [op xs]
+(defn- chain-cmp [op opname xs]
+  # 1-arity (e.g. (< x)) is true regardless of x and does no type check.
+  (when (>= (length xs) 2) (each x xs (need-num x opname)))
   (var ok true) (var i 0)
   (while (and ok (< i (dec (length xs))))
     (unless (op (in xs i) (in xs (+ i 1))) (set ok false))
     (++ i))
   ok)
-(defn core-< [& xs] (chain-cmp < xs))
-(defn core-> [& xs] (chain-cmp > xs))
-(defn core-<= [& xs] (chain-cmp <= xs))
-(defn core->= [& xs] (chain-cmp >= xs))
+(defn core-< [& xs] (chain-cmp < "<" xs))
+(defn core-> [& xs] (chain-cmp > ">" xs))
+(defn core-<= [& xs] (chain-cmp <= "<=" xs))
+(defn core->= [& xs] (chain-cmp >= ">=" xs))
 
 # ============================================================
 # Collections
diff --git a/test/integration/clojure-test-suite-test.janet b/test/integration/clojure-test-suite-test.janet
index 5d6c0e0..711a7ac 100644
--- a/test/integration/clojure-test-suite-test.janet
+++ b/test/integration/clojure-test-suite-test.janet
@@ -18,7 +18,7 @@
 
 # Baseline: assertions Jolt currently passes across the suite. Raise as Jolt
 # improves so a regression (previously-passing assertion breaking) is caught.
-(def baseline-pass 3690)
+(def baseline-pass 3730)
 # A file is "clean" when it ran with zero failures AND zero errors.
 (def baseline-clean-files 45)
 # Per-file wall-clock budget (seconds). Normal files finish in well under 1s;
diff --git a/test/integration/systematic-coverage-test.janet b/test/integration/systematic-coverage-test.janet
index eee08de..14fd485 100644
--- a/test/integration/systematic-coverage-test.janet
+++ b/test/integration/systematic-coverage-test.janet
@@ -59,7 +59,8 @@
 (let [ctx (init)]
   (assert (= true (ct-eval ctx "(zero? 0)")) "zero? 0")
   (assert (= false (ct-eval ctx "(zero? 1)")) "zero? 1")
-  (assert (= false (ct-eval ctx "(zero? nil)")) "zero? nil")
+  # zero?/pos?/neg? now reject non-numbers (Clojure-strict), like the JVM.
+  (assert (not ((protect (ct-eval ctx "(zero? nil)")) 0)) "zero? nil throws")
   (assert (= true (ct-eval ctx "(pos? 1)")) "pos?")
   (assert (= false (ct-eval ctx "(pos? 0)")) "pos? 0")
   (assert (= false (ct-eval ctx "(pos? -1)")) "pos? -1")
diff --git a/test/spec/numbers-spec.janet b/test/spec/numbers-spec.janet
index d79eb7d..54f32cc 100644
--- a/test/spec/numbers-spec.janet
+++ b/test/spec/numbers-spec.janet
@@ -90,6 +90,25 @@
   ["exponent"           "1000.0" "1e3"]
   ["exponent neg"       "0.015"  "1.5e-2"])
 
+# Strictness: numeric ops reject non-numbers like Clojure; the integer
+# predicates reject non-integers; quot/rem/mod reject zero/non-finite.
+(defspec "numbers / strictness (throws like Clojure)"
+  ["odd? nil"           :throws  "(odd? nil)"]
+  ["odd? fractional"    :throws  "(odd? 1.5)"]
+  ["even? inf"          :throws  "(even? ##Inf)"]
+  ["zero? nil"          :throws  "(zero? nil)"]
+  ["pos? false"         :throws  "(pos? false)"]
+  ["neg? keyword"       :throws  "(neg? :a)"]
+  ["< nil"              :throws  "(< nil 1)"]
+  ["> with nil"         :throws  "(> 1 nil)"]
+  ["max non-number"     :throws  "(max 1 nil)"]
+  ["quot by zero"       :throws  "(quot 10 0)"]
+  ["quot inf"           :throws  "(quot ##Inf 1)"]
+  ["< arity-1 any"      "true"   "(< :anything)"]
+  ["odd? ok"            "true"   "(odd? 3)"]
+  ["< ok"               "true"   "(< 1 2 3)"]
+  ["quot ok"            "3"      "(quot 10 3)"])
+
 (defspec "numbers / printing of inf & nan"
   ["str Infinity"       "\"Infinity\""  "(str ##Inf)"]
   ["str -Infinity"      "\"-Infinity\"" "(str ##-Inf)"]