diff --git a/CLAUDE.md b/CLAUDE.md
index 1570e98fc8..fe924e2522 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -8,7 +8,7 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 
 Perry is a native TypeScript compiler written in Rust that compiles TypeScript source code directly to native executables. It uses SWC for TypeScript parsing and LLVM for code generation.
 
-**Current Version:** 0.5.1385
+**Current Version:** 0.5.1386
 
 
 ## TypeScript Parity Status
diff --git a/Cargo.lock b/Cargo.lock
index 595c466a80..0d37bf2099 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -5547,7 +5547,7 @@ checksum = "9b4f627cb1b25917193a259e49bdad08f671f8d9708acfd5fe0a8c1455d87220"
 
 [[package]]
 name = "perry"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "anyhow",
  "base64",
@@ -5607,14 +5607,14 @@ dependencies = [
 
 [[package]]
 name = "perry-api-manifest"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "serde",
 ]
 
 [[package]]
 name = "perry-audio-miniaudio"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "cc",
  "libc",
@@ -5622,7 +5622,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "anyhow",
  "inkwell",
@@ -5639,7 +5639,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-arkts"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "anyhow",
  "perry-hir",
@@ -5647,7 +5647,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-glance"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "anyhow",
  "perry-hir",
@@ -5655,7 +5655,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-js"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "anyhow",
  "perry-dispatch",
@@ -5664,7 +5664,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-swiftui"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "anyhow",
  "perry-hir",
@@ -5672,7 +5672,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-wasm"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "anyhow",
  "base64",
@@ -5684,7 +5684,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-wear-tiles"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "anyhow",
  "perry-hir",
@@ -5692,7 +5692,7 @@ dependencies = [
 
 [[package]]
 name = "perry-container-compose"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "anyhow",
  "async-trait",
@@ -5721,14 +5721,14 @@ dependencies = [
 
 [[package]]
 name = "perry-container-e2e"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "anyhow",
 ]
 
 [[package]]
 name = "perry-diagnostics"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "serde",
  "serde_json",
@@ -5736,7 +5736,7 @@ dependencies = [
 
 [[package]]
 name = "perry-dispatch"
-version = "0.5.1385"
+version = "0.5.1386"
 
 [[package]]
 name = "perry-doc-fixture-my-bindings"
@@ -5747,7 +5747,7 @@ dependencies = [
 
 [[package]]
 name = "perry-doc-tests"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "anyhow",
  "clap",
@@ -5762,7 +5762,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-ads"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "block2",
  "objc2",
@@ -5772,7 +5772,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-argon2"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "argon2",
  "perry-ffi",
@@ -5780,7 +5780,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-axios"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "perry-ffi",
  "reqwest",
@@ -5789,7 +5789,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-bcrypt"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "bcrypt",
  "perry-ffi",
@@ -5797,7 +5797,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-better-sqlite3"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "perry-ffi",
  "rusqlite",
@@ -5805,7 +5805,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-cheerio"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "perry-ffi",
  "scraper",
@@ -5813,7 +5813,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-commander"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "perry-ffi",
  "perry-runtime",
@@ -5821,7 +5821,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-cron"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "chrono",
  "cron",
@@ -5831,7 +5831,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-dayjs"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "chrono",
  "perry-ffi",
@@ -5839,7 +5839,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-decimal"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "perry-ffi",
  "rust_decimal",
@@ -5847,7 +5847,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-dotenv"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "perry-ffi",
  "serde_json",
@@ -5855,7 +5855,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-ethers"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "perry-ffi",
  "rand 0.10.1",
@@ -5863,7 +5863,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-events"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "perry-ffi",
  "perry-runtime",
@@ -5871,14 +5871,14 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-exponential-backoff"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "perry-ffi",
 ]
 
 [[package]]
 name = "perry-ext-fastify"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "bytes",
  "http-body-util",
@@ -5896,7 +5896,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-fetch"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "bytes",
  "lazy_static",
@@ -5909,7 +5909,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-http"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "bytes",
  "h2",
@@ -5933,7 +5933,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-ioredis"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "lazy_static",
  "perry-ffi",
@@ -5943,7 +5943,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-jsonwebtoken"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "base64",
  "jsonwebtoken",
@@ -5954,7 +5954,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-lru-cache"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "lru",
  "perry-ffi",
@@ -5963,7 +5963,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-moment"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "chrono",
  "perry-ffi",
@@ -5971,7 +5971,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-mongodb"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "bson",
  "futures-util",
@@ -5983,7 +5983,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-mysql2"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "chrono",
  "perry-ffi",
@@ -5993,7 +5993,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-nanoid"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "nanoid",
  "perry-ffi",
@@ -6002,7 +6002,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-net"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "bytes",
  "perry-ffi",
@@ -6015,7 +6015,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-node-forge"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "const-oid 0.9.6",
  "der 0.7.10",
@@ -6034,7 +6034,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-nodemailer"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "lettre",
  "perry-ffi",
@@ -6044,7 +6044,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-pdf"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "perry-ffi",
  "printpdf",
@@ -6052,7 +6052,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-pg"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "perry-ffi",
  "sqlx",
@@ -6061,7 +6061,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-ratelimit"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "governor",
  "perry-ffi",
@@ -6069,7 +6069,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-sharp"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "fast_image_resize",
  "image",
@@ -6079,14 +6079,14 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-slugify"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "perry-ffi",
 ]
 
 [[package]]
 name = "perry-ext-streams"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "lazy_static",
  "perry-ffi",
@@ -6095,7 +6095,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-undici"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "perry-ffi",
  "perry-runtime",
@@ -6104,7 +6104,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-uuid"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "perry-ffi",
  "uuid",
@@ -6112,7 +6112,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-validator"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "perry-ffi",
  "regex",
@@ -6122,7 +6122,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-ws"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "futures-util",
  "lazy_static",
@@ -6135,7 +6135,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-zlib"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "brotli",
  "flate2",
@@ -6145,7 +6145,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ffi"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "dashmap",
  "once_cell",
@@ -6154,7 +6154,7 @@ dependencies = [
 
 [[package]]
 name = "perry-hir"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "anyhow",
  "perry-api-manifest",
@@ -6172,7 +6172,7 @@ dependencies = [
 
 [[package]]
 name = "perry-parser"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "anyhow",
  "perry-diagnostics",
@@ -6184,7 +6184,7 @@ dependencies = [
 
 [[package]]
 name = "perry-runtime"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "anyhow",
  "base64",
@@ -6226,14 +6226,14 @@ dependencies = [
 
 [[package]]
 name = "perry-runtime-static"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "perry-runtime",
 ]
 
 [[package]]
 name = "perry-stdlib"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "aes 0.8.4",
  "aes 0.9.1",
@@ -6328,14 +6328,14 @@ dependencies = [
 
 [[package]]
 name = "perry-stdlib-static"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "perry-stdlib",
 ]
 
 [[package]]
 name = "perry-transform"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "anyhow",
  "perry-hir",
@@ -6344,14 +6344,14 @@ dependencies = [
 
 [[package]]
 name = "perry-ui"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "perry-ui-model",
 ]
 
 [[package]]
 name = "perry-ui-android"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "base64",
  "itoa",
@@ -6368,7 +6368,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-geisterhand"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "rand 0.10.1",
  "serde",
@@ -6378,7 +6378,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-gtk4"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "base64",
  "cairo-rs 0.22.0",
@@ -6401,7 +6401,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-ios"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "base64",
  "block2",
@@ -6417,7 +6417,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-macos"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "base64",
  "block2",
@@ -6432,7 +6432,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-model"
-version = "0.5.1385"
+version = "0.5.1386"
 
 [[package]]
 name = "perry-ui-test"
@@ -6443,11 +6443,11 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-testkit"
-version = "0.5.1385"
+version = "0.5.1386"
 
 [[package]]
 name = "perry-ui-tvos"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "base64",
  "block2",
@@ -6463,7 +6463,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-visionos"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "base64",
  "block2",
@@ -6479,7 +6479,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-watchos"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "block2",
  "libc",
@@ -6492,7 +6492,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-windows"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "base64",
  "libc",
@@ -6509,14 +6509,14 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-windows-winui"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "perry-ui-windows",
 ]
 
 [[package]]
 name = "perry-updater"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "anyhow",
  "base64",
@@ -6532,7 +6532,7 @@ dependencies = [
 
 [[package]]
 name = "perry-wasm-host"
-version = "0.5.1385"
+version = "0.5.1386"
 dependencies = [
  "wasmi",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index a25b6692d0..3513254ea5 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -315,7 +315,7 @@ codegen-units = 16
 codegen-units = 16
 
 [workspace.package]
-version = "0.5.1385"
+version = "0.5.1386"
 edition = "2021"
 license = "MIT"
 repository = "https://github.com/PerryTS/perry"
diff --git a/changelog.d/7681-alloca-type-prefix-match.md b/changelog.d/7681-alloca-type-prefix-match.md
new file mode 100644
index 0000000000..bff9bd2d02
--- /dev/null
+++ b/changelog.d/7681-alloca-type-prefix-match.md
@@ -0,0 +1,37 @@
+### Fixed
+
+**The root-slot readers matched an alloca's whole def text, so one `align`
+suffix would have made every negative rooting gate vacuous again (#7675
+follow-up).**
+
+`testing::temp_slots::temp_root_slots` selected slots with
+`matches!(defs.get(slot), Some(&"alloca i64") | Some(&"alloca ptr addrspace(1)"))`.
+If codegen ever printed `alloca i64, align 8`, that filter would match nothing,
+`temp_root_slots` would return an empty vector, and **every
+`assert_no_temp_rooting` in the tree would pass for a program that roots** —
+which is the exact vacuity #7503 was opened to remove. The positive assertions
+would have gone red, so the risk was bounded; the negatives would have lost
+their meaning silently.
+
+All three places that compared whole def text now go through one shared
+`root_slots::alloca_type`, which reads the type and ignores anything after it:
+`temp_slots::temp_root_slots` (the silent case), `root_slots::classify` (loud —
+an unmatched type hits its panic arm — but it would have panicked on a perfectly
+valid spelling) and `root_slots::value_slot_barriers`. Two regression tests
+(`an_aligned_alloca_is_still_recognised_as_a_temp_slot`,
+`an_aligned_alloca_is_still_classified`) fail against the old compare and pass
+against the new one; each asserts its own substitution applied, so neither can
+pass by testing an unmodified fixture.
+
+Two smaller repairs from the same review:
+
+* `temp_root_coverage`'s accumulator write-back clause compared registers
+  exactly while every neighbouring clause went through `slot_holding`, which
+  tolerates the one NaN-boxing step a raw allocation result takes before it
+  reaches a slot. A lowering that boxed the push result would have failed a test
+  whose contract still held. It now uses `slot_holding` too.
+* `zero_seeded_slots` had a load-specific second pass that re-inserted slots the
+  generic `, ptr %s` scan above it had already caught. Removed, with a comment
+  saying why there is deliberately no load-specific pass — an extra branch that
+  reads as coverage it does not add is the same category of problem as the rest
+  of this area.
diff --git a/crates/perry-codegen/src/temp_root_coverage/mod.rs b/crates/perry-codegen/src/temp_root_coverage/mod.rs
index cd145a6fbc..f54ee69e44 100644
--- a/crates/perry-codegen/src/temp_root_coverage/mod.rs
+++ b/crates/perry-codegen/src/temp_root_coverage/mod.rs
@@ -219,10 +219,13 @@ fn console_argument_accumulator_is_rooted_re_read_and_written_back() {
         let slot = slot_holding(&ir, &alloc).expect("assert_rooted_across just found it");
         let push = first_call_result(&ir, "js_array_push_f64")
             .unwrap_or_else(|| panic!("{lowering}: no push:\n{ir}"));
-        assert!(
-            slot_traffic(&ir)[&slot]
-                .iter()
-                .any(|e| matches!(e, SlotEvent::Store { value, .. } if *value == push)),
+        // Through `slot_holding`, not an exact register compare: the store-back
+        // is allowed the same one boxing step every other clause here tolerates,
+        // so an exact match would fail on a lowering that boxes the push result
+        // while the contract still holds (#7675 review).
+        assert_eq!(
+            slot_holding(&ir, &push).as_deref(),
+            Some(slot.as_str()),
             "{lowering}: the reallocated array {push} must be written BACK into \
              {slot}; rooting only the pre-push pointer protects the wrong \
              allocation (#6951):\n{ir}"
diff --git a/crates/perry-codegen/src/testing/root_slots.rs b/crates/perry-codegen/src/testing/root_slots.rs
index 4ccb9df06c..c228640aef 100644
--- a/crates/perry-codegen/src/testing/root_slots.rs
+++ b/crates/perry-codegen/src/testing/root_slots.rs
@@ -73,12 +73,22 @@ fn bind_slot(line: &str) -> Option<&str> {
     slot.starts_with('%').then_some(slot)
 }
 
+/// The TYPE of an `alloca` definition, ignoring anything after it.
+///
+/// Matching the whole def text (`Some(&"alloca i64")`) is one `align 8` away
+/// from matching nothing — and in `temp_slots::temp_root_slots`' sibling filter
+/// that would have emptied the result and turned every negative assertion
+/// vacuous again, which is the defect this whole area is being repaired for.
+/// Raised by review on #7675.
+pub fn alloca_type(def: &str) -> Option<&str> {
+    def.strip_prefix("alloca ")
+        .map(|rest| rest.split(',').next().unwrap_or(rest).trim())
+}
+
 fn classify(fn_ir: &str, defs: &BTreeMap<&str, &str>, slot: &str) -> SlotKind {
-    match defs.get(slot) {
-        Some(&"alloca double") => SlotKind::Value,
-        Some(&"alloca i64") if fn_ir.contains(&format!("store i64 0, ptr {slot}\n")) => {
-            SlotKind::TempRoot
-        }
+    match defs.get(slot).copied().and_then(alloca_type) {
+        Some("double") => SlotKind::Value,
+        Some("i64") if fn_ir.contains(&format!("store i64 0, ptr {slot}\n")) => SlotKind::TempRoot,
         other => panic!(
             "root slot {slot} is bound but its alloca ({other:?}) belongs to no \
              known slot family. Adding one is fine — classify it HERE, in \
@@ -166,7 +176,12 @@ pub fn value_slot_barriers(fn_ir: &str) -> usize {
     let defs = defs(fn_ir);
     barriers_by_slot(fn_ir)
         .into_iter()
-        .filter(|(slot, _)| matches!(defs.get(slot.as_str()), Some(&"alloca double")))
+        .filter(|(slot, _)| {
+            matches!(
+                defs.get(slot.as_str()).copied().and_then(alloca_type),
+                Some("double")
+            )
+        })
         .map(|(_, count)| count)
         .sum()
 }
@@ -296,6 +311,20 @@ entry.0:
         );
     }
 
+    /// An `align` suffix must not push a known slot into the unclassified
+    /// panic arm. Sabotage: restore the exact `Some(&"alloca double")` compare
+    /// and this test panics instead of counting.
+    #[test]
+    fn an_aligned_alloca_is_still_classified() {
+        let aligned = MIXED
+            .replace("%v = alloca double", "%v = alloca double, align 8")
+            .replace("%t = alloca i64", "%t = alloca i64, align 8");
+        assert_ne!(aligned, MIXED, "the substitution must actually apply");
+        assert_eq!(value_slot_binds(&aligned), 1);
+        assert_eq!(temp_root_slot_binds(&aligned), 2);
+        assert_eq!(value_slot_barriers(&aligned), 1);
+    }
+
     /// An `alloca i64` that is NOT null-initialised at entry is not a temp-root
     /// slot; the frame base-index alloca is one such, and mistaking it for a
     /// pool slot would let a real regression hide in the temp bucket.
diff --git a/crates/perry-codegen/src/testing/temp_slots.rs b/crates/perry-codegen/src/testing/temp_slots.rs
index f0c390db54..74c0e9afc5 100644
--- a/crates/perry-codegen/src/testing/temp_slots.rs
+++ b/crates/perry-codegen/src/testing/temp_slots.rs
@@ -388,6 +388,11 @@ pub fn zero_seeded_slots(fn_ir: &str) -> std::collections::BTreeSet<String> {
             touched.insert(slot);
             continue;
         }
+        // Every other mention of the slot — a store of a real value, a load out
+        // of it, an operand — marks it touched. `, ptr %s` covers all of them,
+        // loads included (`%d = load i64, ptr %s`), so there is deliberately no
+        // second load-specific pass: an extra branch that re-inserts what this
+        // one already caught reads as coverage it does not add (#7675 review).
         for slot in line
             .split(", ptr ")
             .skip(1)
@@ -397,20 +402,6 @@ pub fn zero_seeded_slots(fn_ir: &str) -> std::collections::BTreeSet<String> {
         {
             touched.insert(slot);
         }
-        if let Some((_, def)) = line.split_once(" = ") {
-            for prefix in [
-                "load i64, ptr ",
-                "load double, ptr ",
-                "load ptr addrspace(1), ptr ",
-            ] {
-                if let Some(rest) = def.trim().strip_prefix(prefix) {
-                    let slot = rest.split(',').next().unwrap_or(rest).trim().to_string();
-                    if slot.starts_with('%') {
-                        touched.insert(slot);
-                    }
-                }
-            }
-        }
     }
     seeded
 }
@@ -445,9 +436,16 @@ pub fn temp_root_slots(fn_ir: &str) -> Vec<String> {
         .into_iter()
         .filter(|(slot, _)| seeded.contains(slot))
         .filter(|(slot, _)| {
+            // Match the alloca's TYPE, not the whole def text: one `align 8`
+            // suffix away, an exact comparison matches nothing, this filter
+            // empties the result and every `assert_no_temp_rooting` in the tree
+            // goes vacuous — the exact failure #7503 exists to remove. Raised by
+            // review on #7675.
             matches!(
-                defs.get(slot.as_str()),
-                Some(&"alloca i64") | Some(&"alloca ptr addrspace(1)")
+                defs.get(slot.as_str())
+                    .copied()
+                    .and_then(super::root_slots::alloca_type),
+                Some("i64") | Some("ptr addrspace(1)")
             )
         })
         .filter(|(_, events)| events.iter().any(|e| matches!(e, SlotEvent::Store { .. })))
@@ -601,6 +599,28 @@ entry.0:
         );
     }
 
+    /// An `align` suffix on the alloca must not empty the slot set.
+    ///
+    /// This is the shape the exact `Some(&"alloca i64")` compare could not see,
+    /// and its failure mode was the silent one: `temp_root_slots` returns
+    /// nothing, so every `assert_no_temp_rooting` in the tree passes for a
+    /// program that roots. Sabotage: restore the exact compare and this test
+    /// fails while none of the positives do.
+    #[test]
+    fn an_aligned_alloca_is_still_recognised_as_a_temp_slot() {
+        let aligned = SHADOW.replace("%s = alloca i64", "%s = alloca i64, align 8");
+        assert_ne!(aligned, SHADOW, "the substitution must actually apply");
+        assert_eq!(
+            temp_root_slots(&aligned),
+            vec!["%s".to_string()],
+            "an `align` suffix must not hide the slot — an emptied slot set \
+             makes every negative gate vacuous (#7675 review)"
+        );
+        assert!(
+            std::panic::catch_unwind(move || assert_no_temp_rooting(&aligned, "sabotage")).is_err()
+        );
+    }
+
     #[test]
     fn the_negative_direction_sees_real_rooting() {
         assert!(