diff --git a/c/output/lrec_writer_json.c b/c/output/lrec_writer_json.c
index 71acd503c..0c9125463 100644
--- a/c/output/lrec_writer_json.c
+++ b/c/output/lrec_writer_json.c
@@ -9,6 +9,7 @@ typedef struct _lrec_writer_json_state_t {
 	char* output_json_flatten_separator;
 
 	int quote_json_values_always;
+	char* line_indent;
 	char* before_records_at_start_of_stream;
 	char* between_records_after_start_of_stream;
 	char* after_records_at_end_of_stream;
@@ -30,6 +31,7 @@ lrec_writer_t* lrec_writer_json_alloc(int stack_vertically, int wrap_json_output
 	pstate->counter = 0;
 	pstate->output_json_flatten_separator = output_json_flatten_separator;
 
+	pstate->line_indent                           = wrap_json_output_in_outer_list ? "  "  : "";
 	pstate->before_records_at_start_of_stream     = wrap_json_output_in_outer_list ? "[\n" : "";
 	pstate->between_records_after_start_of_stream = wrap_json_output_in_outer_list ? ","   : "";
 	pstate->after_records_at_end_of_stream        = wrap_json_output_in_outer_list ? "]\n" : "";
diff --git a/c/reg_test/expected/out b/c/reg_test/expected/out
index 2bbae4ced..443611213 100644
--- a/c/reg_test/expected/out
+++ b/c/reg_test/expected/out
@@ -33244,6 +33244,31 @@ zee wye 8  0.5985540091064224  0.976181385699006   9.574735  8
 hat wye 9  0.03144187646093577 0.7495507603507059  9.780993  9
 pan wye 10 0.5026260055412137  0.9526183602969864  11.455244 10
 
+mlr --from ./reg_test/input/abixy put 
+  func f(x,y,z) {
+    return x + y + z
+  }
+  subr s(a,b) {
+      $[a] = b;
+      return 1 # subr must not return value
+  }
+  $o = f($x, $y, $i);
+  call s("W", NR);
+
+mlr: return statements within user-defined subroutines must not return a value.
+
+mlr --from ./reg_test/input/abixy put 
+  func f(x,y,z) {
+    return # func must return value
+  }
+  subr s(a,b) {
+      $[a] = b;
+  }
+  $o = f($x, $y, $i);
+  call s("W", NR);
+
+mlr: return statements within user-defined functions must return a value.
+
 
 ================================================================
 MULTI-PART SCRIPTS