diff --git a/extmod/modujson.c b/extmod/modujson.c
index bee432db2..9a73e4501 100644
--- a/extmod/modujson.c
+++ b/extmod/modujson.c
@@ -270,7 +270,7 @@ STATIC mp_obj_t mod_ujson_load(mp_obj_t stream_obj) {
                     S_NEXT(s);
                 }
                 if (flt) {
-                    next = mp_parse_num_decimal(vstr.buf, vstr.len, false, false, NULL);
+                    next = mp_parse_num_float(vstr.buf, vstr.len, false, NULL);
                 } else {
                     next = mp_parse_num_integer(vstr.buf, vstr.len, 10, NULL);
                 }
diff --git a/py/objcomplex.c b/py/objcomplex.c
index 56c8353e9..157617e15 100644
--- a/py/objcomplex.c
+++ b/py/objcomplex.c
@@ -83,7 +83,7 @@ STATIC mp_obj_t complex_make_new(const mp_obj_type_t *type_in, size_t n_args, si
                 // a string, parse it
                 size_t l;
                 const char *s = mp_obj_str_get_data(args[0], &l);
-                return mp_parse_num_decimal(s, l, true, true, NULL);
+                return mp_parse_num_complex(s, l, NULL);
             } else if (mp_obj_is_type(args[0], &mp_type_complex)) {
                 // a complex, just return it
                 return args[0];
diff --git a/py/objfloat.c b/py/objfloat.c
index 0855baac8..8e89b3da3 100644
--- a/py/objfloat.c
+++ b/py/objfloat.c
@@ -137,7 +137,7 @@ STATIC mp_obj_t float_make_new(const mp_obj_type_t *type_in, size_t n_args, size
             mp_buffer_info_t bufinfo;
             if (mp_get_buffer(args[0], &bufinfo, MP_BUFFER_READ)) {
                 // a textual representation, parse it
-                return mp_parse_num_decimal(bufinfo.buf, bufinfo.len, false, false, NULL);
+                return mp_parse_num_float(bufinfo.buf, bufinfo.len, false, NULL);
             } else if (mp_obj_is_float(args[0])) {
                 // a float, just return it
                 return args[0];
diff --git a/py/parse.c b/py/parse.c
index 14f5f6c10..d58098af2 100644
--- a/py/parse.c
+++ b/py/parse.c
@@ -591,7 +591,7 @@ STATIC void push_result_token(parser_t *parser, uint8_t rule_id) {
         mp_obj_t o = mp_parse_num_integer(lex->vstr.buf, lex->vstr.len, 0, lex);
         pn = make_node_const_object_optimised(parser, lex->tok_line, o);
     } else if (lex->tok_kind == MP_TOKEN_FLOAT_OR_IMAG) {
-        mp_obj_t o = mp_parse_num_decimal(lex->vstr.buf, lex->vstr.len, true, false, lex);
+        mp_obj_t o = mp_parse_num_float(lex->vstr.buf, lex->vstr.len, true, lex);
         pn = make_node_const_object(parser, lex->tok_line, o);
     } else if (lex->tok_kind == MP_TOKEN_STRING) {
         // Don't automatically intern all strings.  Doc strings (which are usually large)
diff --git a/py/parsenum.c b/py/parsenum.c
index b90dfaaaf..5e8e5dfe8 100644
--- a/py/parsenum.c
+++ b/py/parsenum.c
@@ -178,7 +178,12 @@ typedef enum {
     PARSE_DEC_IN_EXP,
 } parse_dec_in_t;
 
-mp_obj_t mp_parse_num_decimal(const char *str, size_t len, bool allow_imag, bool force_complex, mp_lexer_t *lex) {
+#if MICROPY_PY_BUILTINS_COMPLEX
+mp_obj_t mp_parse_num_decimal(const char *str, size_t len, bool allow_imag, bool force_complex, mp_lexer_t *lex)
+#else
+mp_obj_t mp_parse_num_float(const char *str, size_t len, bool allow_imag, mp_lexer_t *lex)
+#endif
+{
     #if MICROPY_PY_BUILTINS_FLOAT
 
 // DEC_VAL_MAX only needs to be rough and is used to retain precision while not overflowing
@@ -202,9 +207,9 @@ mp_obj_t mp_parse_num_decimal(const char *str, size_t len, bool allow_imag, bool
     const char *top = str + len;
     mp_float_t dec_val = 0;
     bool dec_neg = false;
-    unsigned int real_imag_state = REAL_IMAG_STATE_START;
 
     #if MICROPY_PY_BUILTINS_COMPLEX
+    unsigned int real_imag_state = REAL_IMAG_STATE_START;
     mp_float_t dec_real = 0;
 parse_start:
     #endif
@@ -325,12 +330,16 @@ parse_start:
     }
 
     if (allow_imag && str < top && (*str | 0x20) == 'j') {
+        #if MICROPY_PY_BUILTINS_COMPLEX
         if (str == str_val_start) {
             // Convert "j" to "1j".
             dec_val = 1;
         }
         ++str;
         real_imag_state |= REAL_IMAG_STATE_HAVE_IMAG;
+        #else
+        raise_exc(mp_obj_new_exception_msg(&mp_type_ValueError, MP_ERROR_TEXT("complex values not supported")), lex);
+        #endif
     }
 
     // negate value if needed
@@ -369,20 +378,16 @@ parse_start:
     #endif
 
     // return the object
+
     #if MICROPY_PY_BUILTINS_COMPLEX
     if (real_imag_state != REAL_IMAG_STATE_START) {
         return mp_obj_new_complex(dec_real, dec_val);
     } else if (force_complex) {
         return mp_obj_new_complex(dec_val, 0);
     }
-    #else
-    if (real_imag_state != REAL_IMAG_STATE_START || force_complex) {
-        raise_exc(mp_obj_new_exception_msg(&mp_type_ValueError, MP_ERROR_TEXT("complex values not supported")), lex);
-    }
     #endif
-    else {
-        return mp_obj_new_float(dec_val);
-    }
+
+    return mp_obj_new_float(dec_val);
 
 value_error:
     raise_exc(mp_obj_new_exception_msg(&mp_type_ValueError, MP_ERROR_TEXT("invalid syntax for number")), lex);
diff --git a/py/parsenum.h b/py/parsenum.h
index a5bed731d..f444632d2 100644
--- a/py/parsenum.h
+++ b/py/parsenum.h
@@ -31,7 +31,21 @@
 #include "py/obj.h"
 
 // these functions raise a SyntaxError if lex!=NULL, else a ValueError
+
 mp_obj_t mp_parse_num_integer(const char *restrict str, size_t len, int base, mp_lexer_t *lex);
+
+#if MICROPY_PY_BUILTINS_COMPLEX
 mp_obj_t mp_parse_num_decimal(const char *str, size_t len, bool allow_imag, bool force_complex, mp_lexer_t *lex);
 
+static inline mp_obj_t mp_parse_num_float(const char *str, size_t len, bool allow_imag, mp_lexer_t *lex) {
+    return mp_parse_num_decimal(str, len, allow_imag, false, lex);
+}
+
+static inline mp_obj_t mp_parse_num_complex(const char *str, size_t len, mp_lexer_t *lex) {
+    return mp_parse_num_decimal(str, len, true, true, lex);
+}
+#else
+mp_obj_t mp_parse_num_float(const char *str, size_t len, bool allow_imag, mp_lexer_t *lex);
+#endif
+
 #endif // MICROPY_INCLUDED_PY_PARSENUM_H
diff --git a/py/persistentcode.c b/py/persistentcode.c
index 6304d1ff0..fbef0b2c0 100644
--- a/py/persistentcode.c
+++ b/py/persistentcode.c
@@ -207,7 +207,7 @@ STATIC mp_obj_t load_obj(mp_reader_t *reader) {
             return mp_parse_num_integer(vstr.buf, vstr.len, 10, NULL);
         } else {
             assert(obj_type == MP_PERSISTENT_OBJ_FLOAT || obj_type == MP_PERSISTENT_OBJ_COMPLEX);
-            return mp_parse_num_decimal(vstr.buf, vstr.len, obj_type == MP_PERSISTENT_OBJ_COMPLEX, false, NULL);
+            return mp_parse_num_float(vstr.buf, vstr.len, obj_type == MP_PERSISTENT_OBJ_COMPLEX, NULL);
         }
     }
 }