diff --git a/extmod/vfs_reader.c b/extmod/vfs_reader.c
index 80d0fa6344..cecef5dc96 100644
--- a/extmod/vfs_reader.c
+++ b/extmod/vfs_reader.c
@@ -49,7 +49,7 @@ typedef struct _mp_reader_vfs_t {
     byte buf[];
 } mp_reader_vfs_t;
 
-static mp_uint_t mp_reader_vfs_readbyte(void *data) {
+static uintptr_t mp_reader_vfs_readbyte(void *data) {
     mp_reader_vfs_t *reader = (mp_reader_vfs_t *)data;
     if (reader->bufpos >= reader->buflen) {
         if (reader->buflen < reader->bufsize) {
@@ -70,10 +70,16 @@ static mp_uint_t mp_reader_vfs_readbyte(void *data) {
     return reader->buf[reader->bufpos++];
 }
 
-static void mp_reader_vfs_close(void *data) {
+static intptr_t mp_reader_vfs_ioctl(void *data, uintptr_t request, uintptr_t arg) {
     mp_reader_vfs_t *reader = (mp_reader_vfs_t *)data;
-    mp_stream_close(reader->file);
-    m_del_obj(mp_reader_vfs_t, reader);
+
+    if (request == MP_READER_CLOSE) {
+        mp_stream_close(reader->file);
+        m_del_obj(mp_reader_vfs_t, reader);
+        return 0;
+    }
+
+    return -MP_EINVAL;
 }
 
 void mp_reader_new_file(mp_reader_t *reader, qstr filename) {
@@ -104,7 +110,7 @@ void mp_reader_new_file(mp_reader_t *reader, qstr filename) {
     rf->bufpos = 0;
     reader->data = rf;
     reader->readbyte = mp_reader_vfs_readbyte;
-    reader->close = mp_reader_vfs_close;
+    reader->ioctl = mp_reader_vfs_ioctl;
 }
 
 #endif // MICROPY_READER_VFS
diff --git a/ports/esp8266/lexerstr32.c b/ports/esp8266/lexerstr32.c
index 51d5658e43..d51c15e7c8 100644
--- a/ports/esp8266/lexerstr32.c
+++ b/ports/esp8266/lexerstr32.c
@@ -26,6 +26,7 @@
  */
 
 #include "py/lexer.h"
+#include "py/mperrno.h"
 
 #if MICROPY_ENABLE_COMPILER
 
@@ -35,7 +36,7 @@ typedef struct _mp_lexer_str32_buf_t {
     uint8_t byte_off;
 } mp_lexer_str32_buf_t;
 
-static mp_uint_t str32_buf_next_byte(void *sb_in) {
+static uintptr_t str32_buf_next_byte(void *sb_in) {
     mp_lexer_str32_buf_t *sb = (mp_lexer_str32_buf_t *)sb_in;
     byte c = sb->val & 0xff;
     if (c == 0) {
@@ -52,9 +53,13 @@ static mp_uint_t str32_buf_next_byte(void *sb_in) {
     return c;
 }
 
-static void str32_buf_free(void *sb_in) {
+static intptr_t str32_buf_free(void *sb_in, uintptr_t request, uintptr_t arg) {
     mp_lexer_str32_buf_t *sb = (mp_lexer_str32_buf_t *)sb_in;
-    m_del_obj(mp_lexer_str32_buf_t, sb);
+    if (request == MP_READER_CLOSE) {
+        m_del_obj(mp_lexer_str32_buf_t, sb);
+        return 0;
+    }
+    return -MP_EINVAL;
 }
 
 mp_lexer_t *mp_lexer_new_from_str32(qstr src_name, const char *str, mp_uint_t len, mp_uint_t free_len) {
diff --git a/ports/nrf/modules/os/microbitfs.c b/ports/nrf/modules/os/microbitfs.c
index f549e6f32e..d8ea5115c9 100644
--- a/ports/nrf/modules/os/microbitfs.c
+++ b/ports/nrf/modules/os/microbitfs.c
@@ -458,11 +458,18 @@ static mp_uint_t microbit_file_write(mp_obj_t obj, const void *buf, mp_uint_t si
     return size;
 }
 
-static void microbit_file_close(file_descriptor_obj *fd) {
-    if (fd->writable) {
-        flash_write_byte((uint32_t)&(file_system_chunks[fd->start_chunk].header.end_offset), fd->seek_offset);
+static intptr_t microbit_file_ioctl(void *fd_in, uintptr_t request, uintptr_t arg) {
+    file_descriptor_obj *fd = fd_in;
+
+    if (request == MP_READER_CLOSE) {
+        if (fd->writable) {
+            flash_write_byte((uint32_t)&(file_system_chunks[fd->start_chunk].header.end_offset), fd->seek_offset);
+        }
+        fd->open = false;
+        return 0;
     }
-    fd->open = false;
+
+    return -MP_EINVAL;
 }
 
 static mp_obj_t microbit_file_list(void) {
@@ -495,7 +502,7 @@ static mp_obj_t microbit_file_size(mp_obj_t filename) {
     return mp_obj_new_int(len);
 }
 
-static mp_uint_t file_read_byte(file_descriptor_obj *fd) {
+static uintptr_t file_read_byte(file_descriptor_obj *fd) {
     if (file_system_chunks[fd->seek_chunk].next_chunk == UNUSED_CHUNK) {
         uint8_t end_offset = file_system_chunks[fd->start_chunk].header.end_offset;
         if (end_offset == UNUSED_CHUNK || fd->seek_offset == end_offset) {
@@ -516,8 +523,8 @@ mp_lexer_t *os_mbfs_new_reader(const char *filename) {
     }
     mp_reader_t reader;
     reader.data = fd;
-    reader.readbyte = (mp_uint_t(*)(void*))file_read_byte;
-    reader.close = (void(*)(void*))microbit_file_close; // no-op
+    reader.readbyte = (uintptr_t(*)(void*))file_read_byte;
+    reader.close = microbit_file_ioctl;
     return mp_lexer_new(qstr_from_str(filename), reader);
 }
 
@@ -538,7 +545,7 @@ static MP_DEFINE_CONST_FUN_OBJ_1(os_mbfs_file_name_obj, os_mbfs_file_name);
 
 static mp_obj_t os_mbfs_file_close(mp_obj_t self) {
     file_descriptor_obj *fd = (file_descriptor_obj*)self;
-    microbit_file_close(fd);
+    microbit_file_ioctl(fd, MP_READER_CLOSE, 0);
     return mp_const_none;
 }
 static MP_DEFINE_CONST_FUN_OBJ_1(os_mbfs_file_close_obj, os_mbfs_file_close);
diff --git a/py/lexer.c b/py/lexer.c
index bff8e63765..1f4a614c5a 100644
--- a/py/lexer.c
+++ b/py/lexer.c
@@ -908,7 +908,7 @@ mp_lexer_t *mp_lexer_new_from_fd(qstr filename, int fd, bool close_fd) {
 
 void mp_lexer_free(mp_lexer_t *lex) {
     if (lex) {
-        lex->reader.close(lex->reader.data);
+        lex->reader.ioctl(lex->reader.data, MP_READER_CLOSE, 0);
         vstr_clear(&lex->vstr);
         #if MICROPY_PY_FSTRINGS
         vstr_clear(&lex->fstring_args);
diff --git a/py/persistentcode.c b/py/persistentcode.c
index 5088c05f03..208231530c 100644
--- a/py/persistentcode.c
+++ b/py/persistentcode.c
@@ -393,9 +393,14 @@ static mp_raw_code_t *load_raw_code(mp_reader_t *reader, mp_module_context_t *co
     return rc;
 }
 
+static void reader_close(void *reader_in) {
+    mp_reader_t *reader = reader_in;
+    reader->ioctl(reader->data, MP_READER_CLOSE, 0);
+}
+
 void mp_raw_code_load(mp_reader_t *reader, mp_compiled_module_t *cm) {
     // Set exception handler to close the reader if an exception is raised.
-    MP_DEFINE_NLR_JUMP_CALLBACK_FUNCTION_1(ctx, reader->close, reader->data);
+    MP_DEFINE_NLR_JUMP_CALLBACK_FUNCTION_1(ctx, reader_close, reader);
     nlr_push_jump_callback(&ctx.callback, mp_call_function_1_from_nlr_jump_callback);
 
     byte header[4];
diff --git a/py/reader.c b/py/reader.c
index 151e04cac2..8232de55ca 100644
--- a/py/reader.c
+++ b/py/reader.c
@@ -39,7 +39,7 @@ typedef struct _mp_reader_mem_t {
     const byte *end;
 } mp_reader_mem_t;
 
-static mp_uint_t mp_reader_mem_readbyte(void *data) {
+static uintptr_t mp_reader_mem_readbyte(void *data) {
     mp_reader_mem_t *reader = (mp_reader_mem_t *)data;
     if (reader->cur < reader->end) {
         return *reader->cur++;
@@ -48,12 +48,18 @@ static mp_uint_t mp_reader_mem_readbyte(void *data) {
     }
 }
 
-static void mp_reader_mem_close(void *data) {
+static intptr_t mp_reader_mem_ioctl(void *data, uintptr_t request, uintptr_t arg) {
     mp_reader_mem_t *reader = (mp_reader_mem_t *)data;
-    if (reader->free_len > 0) {
-        m_del(char, (char *)reader->beg, reader->free_len);
+
+    if (request == MP_READER_CLOSE) {
+        if (reader->free_len > 0) {
+            m_del(char, (char *)reader->beg, reader->free_len);
+        }
+        m_del_obj(mp_reader_mem_t, reader);
+        return 0;
     }
-    m_del_obj(mp_reader_mem_t, reader);
+
+    return -MP_EINVAL;
 }
 
 void mp_reader_new_mem(mp_reader_t *reader, const byte *buf, size_t len, size_t free_len) {
@@ -64,7 +70,7 @@ void mp_reader_new_mem(mp_reader_t *reader, const byte *buf, size_t len, size_t
     rm->end = buf + len;
     reader->data = rm;
     reader->readbyte = mp_reader_mem_readbyte;
-    reader->close = mp_reader_mem_close;
+    reader->ioctl = mp_reader_mem_ioctl;
 }
 
 #if MICROPY_READER_POSIX
@@ -81,7 +87,7 @@ typedef struct _mp_reader_posix_t {
     byte buf[20];
 } mp_reader_posix_t;
 
-static mp_uint_t mp_reader_posix_readbyte(void *data) {
+static uintptr_t mp_reader_posix_readbyte(void *data) {
     mp_reader_posix_t *reader = (mp_reader_posix_t *)data;
     if (reader->pos >= reader->len) {
         if (reader->len == 0) {
@@ -101,14 +107,20 @@ static mp_uint_t mp_reader_posix_readbyte(void *data) {
     return reader->buf[reader->pos++];
 }
 
-static void mp_reader_posix_close(void *data) {
+static intptr_t mp_reader_posix_ioctl(void *data, uintptr_t request, uintptr_t arg) {
     mp_reader_posix_t *reader = (mp_reader_posix_t *)data;
-    if (reader->close_fd) {
-        MP_THREAD_GIL_EXIT();
-        close(reader->fd);
-        MP_THREAD_GIL_ENTER();
+
+    if (request == MP_READER_CLOSE) {
+        if (reader->close_fd) {
+            MP_THREAD_GIL_EXIT();
+            close(reader->fd);
+            MP_THREAD_GIL_ENTER();
+        }
+        m_del_obj(mp_reader_posix_t, reader);
+        return 0;
     }
-    m_del_obj(mp_reader_posix_t, reader);
+
+    return -MP_EINVAL;
 }
 
 void mp_reader_new_file_from_fd(mp_reader_t *reader, int fd, bool close_fd) {
@@ -129,7 +141,7 @@ void mp_reader_new_file_from_fd(mp_reader_t *reader, int fd, bool close_fd) {
     rp->pos = 0;
     reader->data = rp;
     reader->readbyte = mp_reader_posix_readbyte;
-    reader->close = mp_reader_posix_close;
+    reader->ioctl = mp_reader_posix_ioctl;
 }
 
 #if !MICROPY_VFS_POSIX
diff --git a/py/reader.h b/py/reader.h
index 5cb1e67966..7d763e4ff6 100644
--- a/py/reader.h
+++ b/py/reader.h
@@ -28,15 +28,23 @@
 
 #include "py/obj.h"
 
-// the readbyte function must return the next byte in the input stream
-// it must return MP_READER_EOF if end of stream
-// it can be called again after returning MP_READER_EOF, and in that case must return MP_READER_EOF
-#define MP_READER_EOF ((mp_uint_t)(-1))
+#define MP_READER_EOF ((uintptr_t)(-1))
+
+// Reader ioctl request codes.
+#define MP_READER_CLOSE (1)
 
 typedef struct _mp_reader_t {
+    // Pointer to the context of this reader, passed as the first argument to the methods below.
     void *data;
-    mp_uint_t (*readbyte)(void *data);
-    void (*close)(void *data);
+
+    // The readbyte function must return the next byte in the input stream.
+    // It must return MP_READER_EOF if end of stream.  It can be called again after returning
+    // MP_READER_EOF, and in that case must return MP_READER_EOF.
+    uintptr_t (*readbyte)(void *data);
+
+    // Ioctl method for performing various control actions.
+    // On error it must return a negative errno value.
+    intptr_t (*ioctl)(void *data, uintptr_t request, uintptr_t arg);
 } mp_reader_t;
 
 void mp_reader_new_mem(mp_reader_t *reader, const byte *buf, size_t len, size_t free_len);
diff --git a/shared/runtime/pyexec.c b/shared/runtime/pyexec.c
index a305e6a5df..144184705c 100644
--- a/shared/runtime/pyexec.c
+++ b/shared/runtime/pyexec.c
@@ -34,6 +34,7 @@
 #include "py/repl.h"
 #include "py/gc.h"
 #include "py/frozenmod.h"
+#include "py/mperrno.h"
 #include "py/mphal.h"
 #if MICROPY_HW_ENABLE_USB
 #include "irq.h"
@@ -135,7 +136,7 @@ static int parse_compile_execute(const void *source, mp_parse_input_kind_t input
 
         if (exec_flags & EXEC_FLAG_SOURCE_IS_READER) {
             const mp_reader_t *reader = source;
-            reader->close(reader->data);
+            reader->ioctl(reader->data, MP_READER_CLOSE, 0);
         }
 
         // print EOF after normal output
@@ -201,7 +202,7 @@ typedef struct _mp_reader_stdin_t {
     uint16_t window_remain;
 } mp_reader_stdin_t;
 
-static mp_uint_t mp_reader_stdin_readbyte(void *data) {
+static uintptr_t mp_reader_stdin_readbyte(void *data) {
     mp_reader_stdin_t *reader = (mp_reader_stdin_t *)data;
 
     if (reader->eof) {
@@ -233,18 +234,24 @@ static mp_uint_t mp_reader_stdin_readbyte(void *data) {
     return c;
 }
 
-static void mp_reader_stdin_close(void *data) {
+static intptr_t mp_reader_stdin_ioctl(void *data, uintptr_t request, uintptr_t arg) {
     mp_reader_stdin_t *reader = (mp_reader_stdin_t *)data;
-    if (!reader->eof) {
-        reader->eof = true;
-        mp_hal_stdout_tx_strn("\x04", 1); // indicate end to host
-        for (;;) {
-            int c = mp_hal_stdin_rx_chr();
-            if (c == CHAR_CTRL_C || c == CHAR_CTRL_D) {
-                break;
+
+    if (request == MP_READER_CLOSE) {
+        if (!reader->eof) {
+            reader->eof = true;
+            mp_hal_stdout_tx_strn("\x04", 1); // indicate end to host
+            for (;;) {
+                int c = mp_hal_stdin_rx_chr();
+                if (c == CHAR_CTRL_C || c == CHAR_CTRL_D) {
+                    break;
+                }
             }
         }
+        return 0;
     }
+
+    return -MP_EINVAL;
 }
 
 static void mp_reader_new_stdin(mp_reader_t *reader, mp_reader_stdin_t *reader_stdin, uint16_t buf_max) {
@@ -260,7 +267,7 @@ static void mp_reader_new_stdin(mp_reader_t *reader, mp_reader_stdin_t *reader_s
     reader_stdin->window_remain = window;
     reader->data = reader_stdin;
     reader->readbyte = mp_reader_stdin_readbyte;
-    reader->close = mp_reader_stdin_close;
+    reader->ioctl = mp_reader_stdin_ioctl;
 }
 
 static int do_reader_stdin(int c) {