diff --git a/py/compile.c b/py/compile.c
index 778e932823..e332817aaa 100644
--- a/py/compile.c
+++ b/py/compile.c
@@ -51,8 +51,7 @@ typedef struct _compiler_t {
     uint16_t cur_except_level; // increased for SETUP_EXCEPT, SETUP_FINALLY; decreased for POP_BLOCK, POP_EXCEPT
 
     int n_arg_keyword;
-    bool have_star_arg;
-    bool have_dbl_star_arg;
+    uint8_t star_flags;
     bool have_bare_star;
     int param_pass;
     int param_pass_num_dict_params;
@@ -1075,7 +1074,7 @@ void compile_decorated(compiler_t *comp, mp_parse_node_struct_t *pns) {
 
     // call each decorator
     for (int i = 0; i < n - num_built_in_decorators; i++) {
-        EMIT_ARG(call_function, 1, 0, false, false);
+        EMIT_ARG(call_function, 1, 0, 0);
     }
 
     // store func/class object into name
@@ -1422,7 +1421,7 @@ void compile_assert_stmt(compiler_t *comp, mp_parse_node_struct_t *pns) {
     if (!MP_PARSE_NODE_IS_NULL(pns->nodes[1])) {
         // assertion message
         compile_node(comp, pns->nodes[1]);
-        EMIT_ARG(call_function, 1, 0, false, false);
+        EMIT_ARG(call_function, 1, 0, 0);
     }
     EMIT_ARG(raise_varargs, 1);
     EMIT_ARG(label_assign, l_end);
@@ -1873,7 +1872,7 @@ void compile_expr_stmt(compiler_t *comp, mp_parse_node_struct_t *pns) {
             // for REPL, evaluate then print the expression
             EMIT_ARG(load_id, MP_QSTR___repl_print__);
             compile_node(comp, pns->nodes[0]);
-            EMIT_ARG(call_function, 1, 0, false, false);
+            EMIT_ARG(call_function, 1, 0, 0);
             EMIT(pop_top);
 
         } else {
@@ -2219,38 +2218,35 @@ STATIC void compile_trailer_paren_helper(compiler_t *comp, mp_parse_node_t pn_ar
             printf("TypeError: super() call cannot find self\n");
             return;
         }
-        EMIT_ARG(call_function, 2, 0, false, false);
+        EMIT_ARG(call_function, 2, 0, 0);
         return;
     }
 #endif
 
     int old_n_arg_keyword = comp->n_arg_keyword;
-    bool old_have_star_arg = comp->have_star_arg;
-    bool old_have_dbl_star_arg = comp->have_dbl_star_arg;
+    uint old_star_flags = comp->star_flags;
     comp->n_arg_keyword = 0;
-    comp->have_star_arg = false;
-    comp->have_dbl_star_arg = false;
+    comp->star_flags = 0;
 
     compile_node(comp, pn_arglist); // arguments to function call; can be null
 
     // compute number of positional arguments
     int n_positional = n_positional_extra + list_len(pn_arglist, PN_arglist) - comp->n_arg_keyword;
-    if (comp->have_star_arg) {
+    if (comp->star_flags & MP_EMIT_STAR_FLAG_SINGLE) {
         n_positional -= 1;
     }
-    if (comp->have_dbl_star_arg) {
+    if (comp->star_flags & MP_EMIT_STAR_FLAG_DOUBLE) {
         n_positional -= 1;
     }
 
     if (is_method_call) {
-        EMIT_ARG(call_method, n_positional, comp->n_arg_keyword, comp->have_star_arg, comp->have_dbl_star_arg);
+        EMIT_ARG(call_method, n_positional, comp->n_arg_keyword, comp->star_flags);
     } else {
-        EMIT_ARG(call_function, n_positional, comp->n_arg_keyword, comp->have_star_arg, comp->have_dbl_star_arg);
+        EMIT_ARG(call_function, n_positional, comp->n_arg_keyword, comp->star_flags);
     }
 
     comp->n_arg_keyword = old_n_arg_keyword;
-    comp->have_star_arg = old_have_star_arg;
-    comp->have_dbl_star_arg = old_have_dbl_star_arg;
+    comp->star_flags = old_star_flags;
 }
 
 void compile_power_trailers(compiler_t *comp, mp_parse_node_struct_t *pns) {
@@ -2330,7 +2326,7 @@ void compile_comprehension(compiler_t *comp, mp_parse_node_struct_t *pns, scope_
 
     compile_node(comp, pns_comp_for->nodes[1]); // source of the iterator
     EMIT(get_iter);
-    EMIT_ARG(call_function, 1, 0, false, false);
+    EMIT_ARG(call_function, 1, 0, 0);
 }
 
 void compile_atom_paren(compiler_t *comp, mp_parse_node_struct_t *pns) {
@@ -2574,20 +2570,20 @@ void compile_classdef(compiler_t *comp, mp_parse_node_struct_t *pns) {
 }
 
 void compile_arglist_star(compiler_t *comp, mp_parse_node_struct_t *pns) {
-    if (comp->have_star_arg) {
+    if (comp->star_flags & MP_EMIT_STAR_FLAG_SINGLE) {
         compile_syntax_error(comp, (mp_parse_node_t)pns, "can't have multiple *x");
         return;
     }
-    comp->have_star_arg = true;
+    comp->star_flags |= MP_EMIT_STAR_FLAG_SINGLE;
     compile_node(comp, pns->nodes[0]);
 }
 
 void compile_arglist_dbl_star(compiler_t *comp, mp_parse_node_struct_t *pns) {
-    if (comp->have_dbl_star_arg) {
+    if (comp->star_flags & MP_EMIT_STAR_FLAG_DOUBLE) {
         compile_syntax_error(comp, (mp_parse_node_t)pns, "can't have multiple **x");
         return;
     }
-    comp->have_dbl_star_arg = true;
+    comp->star_flags |= MP_EMIT_STAR_FLAG_DOUBLE;
     compile_node(comp, pns->nodes[0]);
 }
 
diff --git a/py/emit.h b/py/emit.h
index 20128fc75b..47ac045af0 100644
--- a/py/emit.h
+++ b/py/emit.h
@@ -14,6 +14,9 @@ typedef enum {
     PASS_3 = 3, // emit code
 } pass_kind_t;
 
+#define MP_EMIT_STAR_FLAG_SINGLE (0x01)
+#define MP_EMIT_STAR_FLAG_DOUBLE (0x02)
+
 typedef struct _emit_t emit_t;
 
 typedef struct _emit_method_table_t {
@@ -98,8 +101,8 @@ typedef struct _emit_method_table_t {
     void (*unpack_ex)(emit_t *emit, int n_left, int n_right);
     void (*make_function)(emit_t *emit, scope_t *scope, uint n_pos_defaults, uint n_kw_defaults);
     void (*make_closure)(emit_t *emit, scope_t *scope, uint n_pos_defaults, uint n_kw_defaults);
-    void (*call_function)(emit_t *emit, int n_positional, int n_keyword, bool have_star_arg, bool have_dbl_star_arg);
-    void (*call_method)(emit_t *emit, int n_positional, int n_keyword, bool have_star_arg, bool have_dbl_star_arg);
+    void (*call_function)(emit_t *emit, int n_positional, int n_keyword, uint star_flags);
+    void (*call_method)(emit_t *emit, int n_positional, int n_keyword, uint star_flags);
     void (*return_value)(emit_t *emit);
     void (*raise_varargs)(emit_t *emit, int n_args);
     void (*yield_value)(emit_t *emit);
diff --git a/py/emitbc.c b/py/emitbc.c
index b2edc25e06..f16ffced11 100644
--- a/py/emitbc.c
+++ b/py/emitbc.c
@@ -767,13 +767,13 @@ STATIC void emit_bc_make_closure(emit_t *emit, scope_t *scope, uint n_pos_defaul
     }
 }
 
-STATIC void emit_bc_call_function_method_helper(emit_t *emit, int stack_adj, uint bytecode_base, int n_positional, int n_keyword, bool have_star_arg, bool have_dbl_star_arg) {
-    if (have_star_arg || have_dbl_star_arg) {
-        if (!have_star_arg) {
+STATIC void emit_bc_call_function_method_helper(emit_t *emit, int stack_adj, uint bytecode_base, int n_positional, int n_keyword, uint star_flags) {
+    if (star_flags) {
+        if (!(star_flags & MP_EMIT_STAR_FLAG_SINGLE)) {
             // load dummy entry for non-existent pos_seq
             emit_bc_load_null(emit);
             emit_bc_rot_two(emit);
-        } else if (!have_dbl_star_arg) {
+        } else if (!(star_flags & MP_EMIT_STAR_FLAG_DOUBLE)) {
             // load dummy entry for non-existent kw_dict
             emit_bc_load_null(emit);
         }
@@ -785,12 +785,12 @@ STATIC void emit_bc_call_function_method_helper(emit_t *emit, int stack_adj, uin
     }
 }
 
-STATIC void emit_bc_call_function(emit_t *emit, int n_positional, int n_keyword, bool have_star_arg, bool have_dbl_star_arg) {
-    emit_bc_call_function_method_helper(emit, 0, MP_BC_CALL_FUNCTION, n_positional, n_keyword, have_star_arg, have_dbl_star_arg);
+STATIC void emit_bc_call_function(emit_t *emit, int n_positional, int n_keyword, uint star_flags) {
+    emit_bc_call_function_method_helper(emit, 0, MP_BC_CALL_FUNCTION, n_positional, n_keyword, star_flags);
 }
 
-STATIC void emit_bc_call_method(emit_t *emit, int n_positional, int n_keyword, bool have_star_arg, bool have_dbl_star_arg) {
-    emit_bc_call_function_method_helper(emit, -1, MP_BC_CALL_METHOD, n_positional, n_keyword, have_star_arg, have_dbl_star_arg);
+STATIC void emit_bc_call_method(emit_t *emit, int n_positional, int n_keyword, uint star_flags) {
+    emit_bc_call_function_method_helper(emit, -1, MP_BC_CALL_METHOD, n_positional, n_keyword, star_flags);
 }
 
 STATIC void emit_bc_return_value(emit_t *emit) {
diff --git a/py/emitcpy.c b/py/emitcpy.c
index 8345c12dca..fe40c4145e 100644
--- a/py/emitcpy.c
+++ b/py/emitcpy.c
@@ -675,24 +675,24 @@ STATIC void emit_cpy_unpack_ex(emit_t *emit, int n_left, int n_right) {
     }
 }
 
-STATIC void emit_cpy_call_function(emit_t *emit, int n_positional, int n_keyword, bool have_star_arg, bool have_dbl_star_arg) {
+STATIC void emit_cpy_call_function(emit_t *emit, int n_positional, int n_keyword, uint star_flags) {
     int s = 0;
-    if (have_star_arg) {
+    if (star_flags & MP_EMIT_STAR_FLAG_SINGLE) {
         s += 1;
     }
-    if (have_dbl_star_arg) {
+    if (star_flags & MP_EMIT_STAR_FLAG_DOUBLE) {
         s += 1;
     }
     emit_pre(emit, -n_positional - 2 * n_keyword - s, 3);
     if (emit->pass == PASS_3) {
-        if (have_star_arg) {
-            if (have_dbl_star_arg) {
+        if (star_flags & MP_EMIT_STAR_FLAG_SINGLE) {
+            if (star_flags & MP_EMIT_STAR_FLAG_DOUBLE) {
                 printf("CALL_FUNCTION_VAR_KW");
             } else {
                 printf("CALL_FUNCTION_VAR");
             }
         } else {
-            if (have_dbl_star_arg) {
+            if (star_flags & MP_EMIT_STAR_FLAG_DOUBLE) {
                 printf("CALL_FUNCTION_KW");
             } else {
                 printf("CALL_FUNCTION");
@@ -702,8 +702,8 @@ STATIC void emit_cpy_call_function(emit_t *emit, int n_positional, int n_keyword
     }
 }
 
-STATIC void emit_cpy_call_method(emit_t *emit, int n_positional, int n_keyword, bool have_star_arg, bool have_dbl_star_arg) {
-    emit_cpy_call_function(emit, n_positional, n_keyword, have_star_arg, have_dbl_star_arg);
+STATIC void emit_cpy_call_method(emit_t *emit, int n_positional, int n_keyword, uint star_flags) {
+    emit_cpy_call_function(emit, n_positional, n_keyword, star_flags);
 }
 
 STATIC void emit_cpy_return_value(emit_t *emit) {
diff --git a/py/emitnative.c b/py/emitnative.c
index a02b125d0c..600960f309 100644
--- a/py/emitnative.c
+++ b/py/emitnative.c
@@ -1200,9 +1200,9 @@ STATIC void emit_native_make_closure(emit_t *emit, scope_t *scope, uint n_pos_de
     assert(0);
 }
 
-STATIC void emit_native_call_function(emit_t *emit, int n_positional, int n_keyword, bool have_star_arg, bool have_dbl_star_arg) {
+STATIC void emit_native_call_function(emit_t *emit, int n_positional, int n_keyword, uint star_flags) {
     // call special viper runtime routine with type info for args, and wanted type info for return
-    assert(!have_star_arg && !have_dbl_star_arg);
+    assert(!star_flags);
 
     /* we no longer have these _n specific call_function's
      * they anyway push args into an array
@@ -1239,8 +1239,8 @@ STATIC void emit_native_call_function(emit_t *emit, int n_positional, int n_keyw
     emit_post_push_reg(emit, VTYPE_PYOBJ, REG_RET);
 }
 
-STATIC void emit_native_call_method(emit_t *emit, int n_positional, int n_keyword, bool have_star_arg, bool have_dbl_star_arg) {
-    assert(!have_star_arg && !have_dbl_star_arg);
+STATIC void emit_native_call_method(emit_t *emit, int n_positional, int n_keyword, uint star_flags) {
+    assert(!star_flags);
 
     /*
     if (n_positional == 0) {