diff --git a/src/julia-syntax.scm b/src/julia-syntax.scm
index aaf07bca7d74a..c8837d90c6d41 100644
--- a/src/julia-syntax.scm
+++ b/src/julia-syntax.scm
@@ -2714,7 +2714,7 @@ f(x) = yt(x)
           ((eq? (car ex) 'method)
            (and (length> ex 2)
                 (assq v (cadr (lam:vinfo (cadddr ex))))))
-          (else #f)))
+          (else (expr-contains-eq v ex))))
   (assert (eq? (car lam) 'lambda))
   (let ((vi (car (lam:vinfo lam))))
     (if (and (any vinfo:capt vi)
diff --git a/test/core.jl b/test/core.jl
index 66ba2ef72368f..d0295b804d87b 100644
--- a/test/core.jl
+++ b/test/core.jl
@@ -4484,3 +4484,10 @@ for (f,g) in ((:asin,:sin), (:acos,:cos))
     f18085(::Type{Val{f}},x...) = map(x->2gx(x), f18085(Val{g},x...))
 end
 @test f18085(Val{:asin},3) === (0.0,)
+
+# issue #18173
+function f18173()
+    identity(()->successflag)
+    successflag = false
+end
+@test f18173() == false