diff --git a/tests/build/build-opts.txt b/tests/build/build-opts.txt
index 04e99e52..93431524 100644
--- a/tests/build/build-opts.txt
+++ b/tests/build/build-opts.txt
@@ -36,6 +36,7 @@ CPPFLAGS=-DSEXP_USE_MUTABLE_STRINGS=0
 CPPFLAGS=-DSEXP_USE_STRING_INDEX_TABLE=1
 CPPFLAGS=-DSEXP_USE_STRICT_TOPLEVEL_BINDINGS=1
 CPPFLAGS=-DSEXP_USE_FIXED_CHUNK_SIZE_HEAPS=1
+CPPFLAGS=-DSEXP_USE_FULL_SOURCE_INFO=0
 CPPFLAGS=-DSEXP_USE_NO_FEATURES=1
 CFLAGS=-std=c89
 CFLAGS=-m32;LDFLAGS=-m32
diff --git a/vm.c b/vm.c
index 907384d3..35e57750 100644
--- a/vm.c
+++ b/vm.c
@@ -678,7 +678,12 @@ static void generate_lambda (sexp ctx, sexp name, sexp loc, sexp lam, sexp lambd
     sexp_context_exception(ctx) = bc;
   } else {
   sexp_bytecode_name(bc) = sexp_lambda_name(lambda);
+#if SEXP_USE_FULL_SOURCE_INFO
+  sexp_bytecode_source(bc) = sexp_cons(ctx, SEXP_NEG_ONE, sexp_lambda_source(lambda));
+  sexp_bytecode_source(bc) = sexp_cons(ctx, sexp_bytecode_source(bc), SEXP_NULL);
+#else
   sexp_bytecode_source(bc) = sexp_lambda_source(lambda);
+#endif
   if (sexp_nullp(fv)) {
     /* shortcut, no free vars */
     tmp = sexp_make_vector(ctx2, SEXP_ZERO, SEXP_VOID);