diff --git a/scheme/last-revision b/scheme/last-revision
index 2b8bb9e..197a77e 100644
--- a/scheme/last-revision
+++ b/scheme/last-revision
@@ -1 +1 @@
-1787
+1788
diff --git a/scheme/psyntax.expander.ss b/scheme/psyntax.expander.ss
index b21bce1..4ec5f41 100644
--- a/scheme/psyntax.expander.ss
+++ b/scheme/psyntax.expander.ss
@@ -2884,10 +2884,10 @@
 
   (define (chi-defun x r mr)
     (syntax-match x ()
-      [(_ (_ . fmls) . body*)
+      [(_ (ctxt . fmls) . body*)
        (let-values (((fmls body)
                      (chi-lambda-clause fmls fmls body* r mr)))
-         (build-lambda (syntax-annotation x) fmls body))]))
+          (build-lambda (syntax-annotation ctxt) fmls body))]))
 
   (define chi-rhs
     (lambda (rhs r mr)