diff --git a/include/chibi/sexp.h b/include/chibi/sexp.h
index 68290edf..bc8311fc 100755
--- a/include/chibi/sexp.h
+++ b/include/chibi/sexp.h
@@ -1346,6 +1346,7 @@ enum sexp_context_globals {
   SEXP_G_RESUMECC_BYTECODE,
   SEXP_G_FINAL_RESUMER,
   SEXP_G_STRICT_P,
+  SEXP_G_NO_TAIL_CALLS_P,
 #if SEXP_USE_FOLD_CASE_SYMS
   SEXP_G_FOLD_CASE_P,
 #endif
diff --git a/main.c b/main.c
index 9a34e370..54feeff4 100644
--- a/main.c
+++ b/main.c
@@ -473,6 +473,10 @@ sexp run_main (int argc, char **argv) {
       init_context(); sexp_global(ctx, SEXP_G_STRICT_P) = SEXP_TRUE;
       handle_noarg();
       break;
+    case 'T':
+      init_context(); sexp_global(ctx, SEXP_G_NO_TAIL_CALLS_P) = SEXP_TRUE;
+      handle_noarg();
+      break;
     case 't':
       mods_loaded = 1;
       load_init(1);
diff --git a/sexp.c b/sexp.c
index 6f939462..82d10c5e 100644
--- a/sexp.c
+++ b/sexp.c
@@ -434,6 +434,7 @@ void sexp_init_context_globals (sexp ctx) {
   sexp_global(ctx, SEXP_G_SYMBOLS) = sexp_make_vector(ctx, sexp_make_fixnum(SEXP_SYMBOL_TABLE_SIZE), SEXP_NULL);
 #endif
   sexp_global(ctx, SEXP_G_STRICT_P) = SEXP_FALSE;
+  sexp_global(ctx, SEXP_G_NO_TAIL_CALLS_P) = SEXP_FALSE;
 #if SEXP_USE_FOLD_CASE_SYMS
   sexp_global(ctx, SEXP_G_FOLD_CASE_P) = sexp_make_boolean(SEXP_DEFAULT_FOLD_CASE_SYMS);
 #endif
diff --git a/vm.c b/vm.c
index 6acdf3ee..a16af9b4 100644
--- a/vm.c
+++ b/vm.c
@@ -475,7 +475,7 @@ static void generate_general_app (sexp ctx, sexp app) {
   sexp_generate(ctx, 0, 0, 0, sexp_car(app));
 
   /* maybe overwrite the current frame */
-  sexp_emit(ctx, (tailp ? SEXP_OP_TAIL_CALL : SEXP_OP_CALL));
+  sexp_emit(ctx, ((tailp && sexp_not(sexp_global(ctx, SEXP_G_NO_TAIL_CALLS_P))) ? SEXP_OP_TAIL_CALL : SEXP_OP_CALL));
   sexp_emit_word(ctx, (sexp_uint_t)sexp_make_fixnum(len));
 
   sexp_context_tailp(ctx) = (char)tailp;