diff --git a/docs/SETUP.md b/docs/SETUP.md
index f28f58e..bf16bf2 100644
--- a/docs/SETUP.md
+++ b/docs/SETUP.md
@@ -88,6 +88,14 @@ patch, and diffing the result against the working tree (byte-identical). It adds
   after a branch/jump so GNU `as` can fill the slot.
 - `--nop-on-reg-read` (region token `maspsx=regread`) — extend the load-delay predicate (cookbook
   finding 27) so a following `jr`/`jalr` that *uses* the loaded register also gets the delay `nop`.
+- **A default-on fix (no region token): maspsx now honours cc1's explicit `#nop` marker.** cc1 emits the
+  marker when it wants a load-delay nop; maspsx used to re-derive the need and could overrule cc1 for a
+  **bare-symbol store** consumer (`sw $2,D_801221C4`), because `uses_at` is True for a macro store while
+  `nop_at_expansion` is False for ASPSX >= 2.30, so neither test fired and the nop was dropped
+  (`0x80107C5C`, `0x8003A9C8`). The fix honours the marker instead of overruling it. **Verified
+  regression-free: `make check` green at 489 regions / 237 tests with all 489 regions byte-identical.**
+  Worker B2 found the gap; the coordinator traced the mechanism after B2's first diagnosis (extend the
+  predicate) proved to be a no-op — the predicate already returned True.
 
 Both default **off**, and `make check` is green at 439 regions with them off, so the matched corpus is
 byte-identical. **Status: implemented, but neither mode has been shown to close a region.** See
diff --git a/tools/patches/maspsx-phase10-r1r2.patch b/tools/patches/maspsx-phase10-r1r2.patch
index 5301b56..4204a89 100644
--- a/tools/patches/maspsx-phase10-r1r2.patch
+++ b/tools/patches/maspsx-phase10-r1r2.patch
@@ -64,7 +64,7 @@
          self.sltu_at = sltu_at
          self.addiu_at = addiu_at
          self.div_uses_tge = div_uses_tge
-@@ -696,7 +739,14 @@
+@@ -696,9 +739,30 @@
      ) -> List[str]:
          res: List[str] = []
  
@@ -79,8 +79,24 @@
 +        if reuse:
              nop_required = False
  
++            # Phase 10 (developer-authorised): cc1 emits an explicit `#nop` marker
++            # when it wants a load-delay nop. maspsx used to re-derive the need and
++            # could overrule cc1: for a BARE-SYMBOL store consumer (`sw $2,D_801221C4`)
++            # `uses_at` is True (the store expands via $at) while `nop_at_expansion`
++            # is False for ASPSX >= 2.30, so neither test below fired and the nop was
++            # dropped -- losing an instruction cc1 had asked for (0x80107C5C,
++            # 0x8003A9C8). Honour the explicit marker instead of overruling it.
++            # Only the marker changes behaviour; every other path is untouched.
++            if self.get_next_instruction(
++                skip=0, ignore_nop=False, ignore_set=True, ignore_label=True
++            ) == "#nop":
++                reason = "cc1 emitted an explicit '#nop' marker"
++                nop_required = True
++
              if not uses_at(next_instruction):
-@@ -1102,7 +1152,7 @@
+                 reason = f"'{next_instruction}' does not use $at"
+                 nop_required = True
+@@ -1102,7 +1166,7 @@
  
          elif op in branch_mnemonics or op in jump_mnemonics:
              res.append(line)