diff --git a/lib/chibi/ast.c b/lib/chibi/ast.c
index 0fb4ad9b..cad16736 100644
--- a/lib/chibi/ast.c
+++ b/lib/chibi/ast.c
@@ -657,6 +657,7 @@ sexp sexp_init_library (sexp ctx, sexp self, sexp_sint_t n, sexp env, const char
   sexp_define_accessors(ctx, env, SEXP_CND, 2, "cnd-fail", "cnd-fail-set!");
   sexp_define_accessors(ctx, env, SEXP_SET, 0, "set-var", "set-var-set!");
   sexp_define_accessors(ctx, env, SEXP_SET, 1, "set-value", "set-value-set!");
+  sexp_define_accessors(ctx, env, SEXP_SET, 2, "set-source", "set-source-set!");
   sexp_define_accessors(ctx, env, SEXP_REF, 0, "ref-name", "ref-name-set!");
   sexp_define_accessors(ctx, env, SEXP_REF, 1, "ref-cell", "ref-cell-set!");
   sexp_define_accessors(ctx, env, SEXP_SEQ, 0, "seq-ls", "seq-ls-set!");
diff --git a/lib/chibi/ast.sld b/lib/chibi/ast.sld
index 6e8ccb6f..2744433c 100644
--- a/lib/chibi/ast.sld
+++ b/lib/chibi/ast.sld
@@ -20,7 +20,7 @@
    lambda-source-set!
    cnd-test cnd-pass cnd-fail
    cnd-test-set! cnd-pass-set! cnd-fail-set!
-   set-var set-value set-var-set! set-value-set!
+   set-var set-value set-var-set! set-value-set! set-source set-source-set!
    ref-name ref-cell ref-name-set! ref-cell-set!
    seq-ls seq-ls-set! lit-value lit-value-set!
    exception-kind exception-message exception-irritants exception-source