diff --git a/docs/test-system-v2.md b/docs/test-system-v2.md
index 373ec439..d7862dea 100644
--- a/docs/test-system-v2.md
+++ b/docs/test-system-v2.md
@@ -32,9 +32,9 @@ categories out of the ordinary developer target.
 | Fixed point and self-host | `test-bootstrap` |
 | Host linker/platform behavior | `test-platform` |
 
-The live declarative compiler corpus has 1,485 fixtures and 2,970 C/WW cells:
+The live declarative compiler corpus has 1,486 fixtures and 2,972 C/WW cells:
 338 expected rejections (314 shared and 24 stage-specific), 17 compile-only
-successes, 191 exit-zero programs, and 939 explicit-exit programs.
+successes, 191 exit-zero programs, and 940 explicit-exit programs.
 
 147 native C carriers remain. They are partitioned exactly once as five
 in-process units, 24 byte/artifact gates, six bootstrap gates, one platform
diff --git a/internal/wwfixture/types.ww b/internal/wwfixture/types.ww
index 8e3c2b40..12210d32 100644
--- a/internal/wwfixture/types.ww
+++ b/internal/wwfixture/types.ww
@@ -1,13 +1,13 @@
 package wwfixture;
 
 def protocolversion: i32 = 1;
-def corpuscount: i32 = 1485;
+def corpuscount: i32 = 1486;
 def errorcount: i32 = 338;
 def compilecount: i32 = 17;
 def runcount: i32 = 191;
-def runexitcount: i32 = 939;
-def nativecount: i32 = 2970;
-def corpushash: str = "69453e64f903a75b8a3f27c79e336ae766b3fb7ecfaac85d13f5d1f0c0dc4f50";
+def runexitcount: i32 = 940;
+def nativecount: i32 = 2972;
+def corpushash: str = "ab4b1d1ffc078b23de0a70911740511e873cd8d6f76009c4719d704bb36e6133";
 
 type directive = enum i32 {
 	ERROR = 0,
diff --git a/selfhost/cmd/wcc/check.ww b/selfhost/cmd/wcc/check.ww
index ff23b92f..4bec0705 100644
--- a/selfhost/cmd/wcc/check.ww
+++ b/selfhost/cmd/wcc/check.ww
@@ -1083,7 +1083,18 @@ fn typeeqast(c: *checker, a: *syntax.node, b: *syntax.node) bool = {
 				let va: bool = pa.op == syntax.tkind.TK_ELLIPSIS;
 				let vb: bool = pb.op == syntax.tkind.TK_ELLIPSIS;
 				if (va != vb) { return false; };
-				if (!typeeqast(c, pa.lhs, pb.lhs)) { return false; };
+				// installparams normalizes a DECL's `T...` param lhs to
+				// a marked []T in place; a fn TYPE expr stays surface.
+				// Peel exactly the marked wrapper so both sides compare
+				// at the declared element type (cstage's type_eq sees
+				// type_slice on BOTH sides, check.c:908-917).
+				let la: *syntax.node = pa.lhs;
+				let lb: *syntax.node = pb.lhs;
+				if (la != nil && la.kind == syntax.nkind.N_TSLICE
+				    && la.op == syntax.tkind.TK_ELLIPSIS) { la = la.lhs; };
+				if (lb != nil && lb.kind == syntax.nkind.N_TSLICE
+				    && lb.op == syntax.tkind.TK_ELLIPSIS) { lb = lb.lhs; };
+				if (!typeeqast(c, la, lb)) { return false; };
 			};
 			pa = pa.next;
 			pb = pb.next;
@@ -6817,6 +6828,14 @@ fn installparams(c: *checker, params: *syntax.node) void = {
 				if (p.lhs != nil && p.lhs.kind != syntax.nkind.N_TSLICE) {
 					let sl: *syntax.node = syntax.newnode(syntax.nkind.N_TSLICE, "", 0, 0);
 					sl.lhs = p.lhs;
+					// op marks the wrapper as THIS normalization, not
+					// surface syntax, so typeeqast can peel exactly it
+					// when comparing against an unnormalized fn TYPE
+					// expr (`let f: fn(args: i64...) void = sum` — the
+					// decl side reads []i64 here, the let side i64).
+					// Param-lhs position never carries a tagged spread
+					// marker, so the op reads stay disjoint.
+					sl.op = syntax.tkind.TK_ELLIPSIS;
 					p.lhs = sl;
 				};
 			};
diff --git a/test/wcc/data/fnptrlet_variadic/case.ww b/test/wcc/data/fnptrlet_variadic/case.ww
new file mode 100644
index 00000000..627c07a3
--- /dev/null
+++ b/test/wcc/data/fnptrlet_variadic/case.ww
@@ -0,0 +1,21 @@
+//ww:run-exit 42
+package main;
+
+// A variadic fn assigned to a fn-typed let and called through it. The
+// wwstage over-rejected the let ("not assignable"): installparams
+// normalizes the DECL's `T...` param lhs to []T in place, while the
+// let's fn TYPE expr stays surface, so typeeqast compared []i64 vs
+// i64. cstage compares resolved types with type_slice on both sides
+// (check.c:908-917) and accepts.
+
+fn tally(args: i64...) i64 = {
+	let s: i64 = 0i64;
+	let i: i32 = 0;
+	for (i < args.len) { s += args[i]; i += 1; };
+	return s;
+};
+
+fn main() i32 = {
+	let f: fn(args: i64...) i64 = tally;
+	return (f(1i64, 2i64, 3i64) * 7i64): i32;
+};