diff --git a/ports/unix/main.c b/ports/unix/main.c
index 1c5c2266aa..934bd3252b 100644
--- a/ports/unix/main.c
+++ b/ports/unix/main.c
@@ -58,7 +58,7 @@
 #include "shared/runtime/pyexec.h"
 
 // Command line options, with their defaults
-static bool compile_only = false;
+bool mp_compile_only = false;
 static uint emit_opt = MP_EMIT_OPT_NONE;
 
 #if MICROPY_ENABLE_GC
@@ -159,7 +159,7 @@ static int execute_from_lexer(int source_kind, const void *source, mp_parse_inpu
 
         mp_obj_t module_fun = mp_compile(&parse_tree, source_name, is_repl);
 
-        if (!compile_only) {
+        if (!mp_compile_only) {
             // execute it
             mp_call_function_0(module_fun);
         }
@@ -325,7 +325,7 @@ static void pre_process_options(int argc, char **argv) {
                 }
                 if (0) {
                 } else if (strcmp(argv[a + 1], "compile-only") == 0) {
-                    compile_only = true;
+                    mp_compile_only = true;
                 } else if (strcmp(argv[a + 1], "emit=bytecode") == 0) {
                     emit_opt = MP_EMIT_OPT_BYTECODE;
                 #if MICROPY_EMIT_NATIVE
diff --git a/ports/unix/mpconfigport.h b/ports/unix/mpconfigport.h
index f074398635..562c93f99b 100644
--- a/ports/unix/mpconfigport.h
+++ b/ports/unix/mpconfigport.h
@@ -151,6 +151,9 @@ typedef long mp_off_t;
 // Enable sys.executable.
 #define MICROPY_PY_SYS_EXECUTABLE (1)
 
+// Enable support for compile-only mode.
+#define MICROPY_PYEXEC_COMPILE_ONLY (1)
+
 #define MICROPY_PY_SOCKET_LISTEN_BACKLOG_DEFAULT (SOMAXCONN < 128 ? SOMAXCONN : 128)
 
 // Bare-metal ports don't have stderr. Printing debug to stderr may give tests
diff --git a/ports/unix/mphalport.h b/ports/unix/mphalport.h
index 0efd6940b3..eb2370c94b 100644
--- a/ports/unix/mphalport.h
+++ b/ports/unix/mphalport.h
@@ -25,6 +25,7 @@
  */
 #include <errno.h>
 #include <unistd.h>
+#include <stdbool.h>
 
 #ifndef CHAR_CTRL_C
 #define CHAR_CTRL_C (3)
@@ -117,3 +118,6 @@ enum {
 
 void mp_hal_get_mac(int idx, uint8_t buf[6]);
 #endif
+
+// Global variable to control compile-only mode.
+extern bool mp_compile_only;
diff --git a/ports/windows/mpconfigport.h b/ports/windows/mpconfigport.h
index 68744ba93e..24c54438e6 100644
--- a/ports/windows/mpconfigport.h
+++ b/ports/windows/mpconfigport.h
@@ -161,6 +161,9 @@
 #define MICROPY_MACHINE_MEM_GET_READ_ADDR   mod_machine_mem_get_addr
 #define MICROPY_MACHINE_MEM_GET_WRITE_ADDR  mod_machine_mem_get_addr
 
+// Enable support for compile-only mode.
+#define MICROPY_PYEXEC_COMPILE_ONLY (1)
+
 #define MICROPY_ERROR_REPORTING     (MICROPY_ERROR_REPORTING_DETAILED)
 #define MICROPY_ERROR_PRINTER       (&mp_stderr_print)
 #define MICROPY_WARNINGS            (1)