diff --git a/lib/lua/parser.sx b/lib/lua/parser.sx
index 9611ea45..7195ee65 100644
--- a/lib/lua/parser.sx
+++ b/lib/lua/parser.sx
@@ -211,6 +211,8 @@
                       (lua-tok-type t)
                       " "
                       (lua-tok-value t))))))))
+        (define parse-pow-chain
+          (fn () (let ((lhs (parse-primary))) (parse-binop-rhs 10 lhs))))
         (set!
           parse-unary
           (fn
@@ -228,7 +230,7 @@
                 (begin
                   (advance-tok!)
                   (list (quote lua-unop) "not" (parse-unary))))
-              (else (parse-primary)))))
+              (else (parse-pow-chain)))))
         (define
           parse-binop-rhs
           (fn
diff --git a/lib/lua/scoreboard.json b/lib/lua/scoreboard.json
index 58f05353..a9d54092 100644
--- a/lib/lua/scoreboard.json
+++ b/lib/lua/scoreboard.json
@@ -11,7 +11,7 @@
   "top_failure_modes": [
     [
       "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
-      10
+      9
     ],
     [
       "timeout",
@@ -21,6 +21,10 @@
       "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"lua: attempt to call non-functio",
       2
     ],
+    [
+      "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"lua: attempt to compare incompat",
+      1
+    ],
     [
       "other: Unhandled exception: \\\"Not callable: nil (kont=10 frames)\\",
       1
@@ -43,7 +47,7 @@
       "name": "attrib.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
-      "ms": 5719
+      "ms": 6000
     },
     {
       "name": "big.lua",
@@ -55,7 +59,7 @@
       "name": "calls.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
-      "ms": 4548
+      "ms": 4946
     },
     {
       "name": "checktable.lua",
@@ -78,8 +82,8 @@
     {
       "name": "constructs.lua",
       "status": "fail",
-      "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
-      "ms": 4153
+      "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"lua: attempt to compare incompat",
+      "ms": 4533
     },
     {
       "name": "db.lua",
@@ -91,13 +95,13 @@
       "name": "errors.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Not callable: nil (kont=10 frames)\\",
-      "ms": 2938
+      "ms": 3217
     },
     {
       "name": "events.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
-      "ms": 6598
+      "ms": 7215
     },
     {
       "name": "files.lua",
@@ -115,13 +119,13 @@
       "name": "literals.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
-      "ms": 1859
+      "ms": 1901
     },
     {
       "name": "locals.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"lua: attempt to call non-functio",
-      "ms": 1687
+      "ms": 1693
     },
     {
       "name": "main.lua",
@@ -133,19 +137,19 @@
       "name": "math.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
-      "ms": 3774
+      "ms": 4095
     },
     {
       "name": "nextvar.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
-      "ms": 6637
+      "ms": 7177
     },
     {
       "name": "pm.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
-      "ms": 5886
+      "ms": 6048
     },
     {
       "name": "sort.lua",
@@ -157,19 +161,19 @@
       "name": "strings.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
-      "ms": 4040
+      "ms": 3990
     },
     {
       "name": "vararg.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"assertion failed!\\\\\\\"\\",
-      "ms": 2064
+      "ms": 2249
     },
     {
       "name": "verybig.lua",
       "status": "fail",
       "reason": "other: Unhandled exception: \\\"Unhandled exception: \\\\\\\"lua: attempt to call non-functio",
-      "ms": 545
+      "ms": 572
     }
   ]
 }
\ No newline at end of file
diff --git a/lib/lua/scoreboard.md b/lib/lua/scoreboard.md
index 1c80f585..eb5d76a2 100644
--- a/lib/lua/scoreboard.md
+++ b/lib/lua/scoreboard.md
@@ -5,9 +5,10 @@ fail=13 timeout=3 skip=8 total=24
 
 ## Top failure modes
 
-- **10x** other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\
+- **9x** other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\
 - **3x** timeout
 - **2x** other: Unhandled exception: \"Unhandled exception: \\\"lua: attempt to call non-functio
+- **1x** other: Unhandled exception: \"Unhandled exception: \\\"lua: attempt to compare incompat
 - **1x** other: Unhandled exception: \"Not callable: nil (kont=10 frames)\
 
 ## Per-test results
@@ -16,25 +17,25 @@ fail=13 timeout=3 skip=8 total=24
 |---|---|---|---:|
 | all.lua | skip | driver uses dofile to chain other tests | 0 |
 | api.lua | skip | requires testC (C debug library) | 0 |
-| attrib.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 5719 |
+| attrib.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 6000 |
 | big.lua | timeout | per-test timeout | 8006 |
-| calls.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 4548 |
+| calls.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 4946 |
 | checktable.lua | skip | internal debug helpers | 0 |
 | closure.lua | timeout | per-test timeout | 8003 |
 | code.lua | skip | bytecode inspection via debug library | 0 |
-| constructs.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 4153 |
+| constructs.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"lua: attempt to compare incompat | 4533 |
 | db.lua | skip | debug library | 0 |
-| errors.lua | fail | other: Unhandled exception: \"Not callable: nil (kont=10 frames)\ | 2938 |
-| events.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 6598 |
+| errors.lua | fail | other: Unhandled exception: \"Not callable: nil (kont=10 frames)\ | 3217 |
+| events.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 7215 |
 | files.lua | skip | io library | 0 |
 | gc.lua | skip | collectgarbage / finalisers | 0 |
-| literals.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 1859 |
-| locals.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"lua: attempt to call non-functio | 1687 |
+| literals.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 1901 |
+| locals.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"lua: attempt to call non-functio | 1693 |
 | main.lua | skip | standalone interpreter driver | 0 |
-| math.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 3774 |
-| nextvar.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 6637 |
-| pm.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 5886 |
+| math.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 4095 |
+| nextvar.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 7177 |
+| pm.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 6048 |
 | sort.lua | timeout | per-test timeout | 8007 |
-| strings.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 4040 |
-| vararg.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 2064 |
-| verybig.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"lua: attempt to call non-functio | 545 |
+| strings.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 3990 |
+| vararg.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"assertion failed!\\\"\ | 2249 |
+| verybig.lua | fail | other: Unhandled exception: \"Unhandled exception: \\\"lua: attempt to call non-functio | 572 |
diff --git a/lib/lua/test.sh b/lib/lua/test.sh
index 09d87cae..c9f8908c 100755
--- a/lib/lua/test.sh
+++ b/lib/lua/test.sh
@@ -928,6 +928,14 @@ cat > "$TMPFILE" << 'EPOCHS'
 (epoch 1831)
 (eval "(lua-eval-ast \"if \\\"\\\\09912\\\" == \\\"c12\\\" then return 1 else return 0 end\")")
 
+;; ── Unary-minus / ^ precedence (Lua spec: ^ tighter than -) ──
+(epoch 1840)
+(eval "(lua-eval-ast \"return -2^2\")")
+(epoch 1841)
+(eval "(lua-eval-ast \"return 2^3^2\")")
+(epoch 1842)
+(eval "(lua-eval-ast \"if -2^2 == -4 then return 1 else return 0 end\")")
+
 EPOCHS
 
 OUTPUT=$(timeout 60 "$SX_SERVER" < "$TMPFILE" 2>/dev/null)
@@ -1401,6 +1409,11 @@ check 1821 "arg[i] access"                  '60'
 check 1830 "\\65 → A"                        '"A"'
 check 1831 "\\099 + 12 → c12"                '1'
 
+# ── Unary-minus / ^ precedence (Lua: ^ tighter than unary -) ──
+check 1840 "-2^2 = -4"                      '-4'
+check 1841 "2^3^2 = 512 (right-assoc)"      '512'
+check 1842 "-2^2 == -4 true"                '1'
+
 TOTAL=$((PASS + FAIL))
 if [ $FAIL -eq 0 ]; then
   echo "ok $PASS/$TOTAL Lua-on-SX tests passed"
diff --git a/plans/lua-on-sx.md b/plans/lua-on-sx.md
index 082f9ab1..29a28e5d 100644
--- a/plans/lua-on-sx.md
+++ b/plans/lua-on-sx.md
@@ -82,6 +82,7 @@ Each item: implement → tests → tick box → update progress log.
 
 _Newest first. Agent appends on every commit._
 
+- 2026-04-24: lua: scoreboard iteration — **unary-minus / `^` precedence fix**. Per Lua spec, `^` binds tighter than unary `-`, so `-2^2` should parse as `-(2^2) = -4`, not `(-2)^2 = 4`. My parser recursed into `parse-unary` and then let `^` bind to the already-negated operand. Added `parse-pow-chain` helper and changed the `else` branch of `parse-unary` to parse a primary + `^`-chain before returning; unary operators now wrap the full `^`-chain. Fixed `constructs.lua` past assert #3 (moved to compare-incompatible). 365/365 green (+3 precedence tests).
 - 2026-04-24: lua: scoreboard iteration — `lua-byte-to-char` regression fix. My previous change returned 2-char strings (`"\a"` etc.) for bytes that SX string literals can't express (0, 7, 8, 11, 12, 14–31, 127+), breaking `'a\0a'` length from 3 → 4. Now only 9/10/13 and printable 32-126 produce real bytes; others use a single `"?"` placeholder so `string.len` stays correct. literals.lua back to failing at assert #4 (was regressed to #2).
 - 2026-04-24: lua: scoreboard iteration — **decimal string escapes** `\ddd` (1-3 digits). Tokenizer `read-string` previously fell through to literal for digits, so `"\65"` came out as `"65"` not `"A"`. Added `read-decimal-escape!` consuming up to 3 digits while keeping value ≤255, plus `\a`/`\b`/`\f`/`\v` control escapes and `lua-byte-to-char` ASCII lookup. 362 tests (+2 escape tests).
 - 2026-04-24: lua: scoreboard iteration — **`loadstring` error propagation**. When `loadstring(s)()` was implemented as `eval-expr ( (let () compiled))`, SX's `eval-expr` wrapped any propagated `raise` as "Unhandled exception: X" — so `error('hi')` inside a loadstring'd chunk came out as that wrapped string instead of the clean `"hi"` Lua expects. Fix: transpile source once into a lambda AST, `eval-expr` it ONCE to get a callable fn value, return that — subsequent calls propagate raises cleanly. Guarded parse-failure path returns `(nil, err)` per Lua convention. vararg.lua now runs past assert #18; errors.lua past parse stage.