diff --git a/py/nlrx86.c b/py/nlrx86.c
index 07ba72628c..58aaa1a571 100644
--- a/py/nlrx86.c
+++ b/py/nlrx86.c
@@ -49,10 +49,9 @@ unsigned int nlr_push(nlr_buf_t *nlr) {
     __asm volatile (
     // Check for Zephyr, which uses a different calling convention
     // by default.
-    // TODO: Better check for Zephyr.
     // TODE: Better support for various x86 calling conventions
     // (unfortunately, __attribute__((naked)) is not supported on x86).
-    #ifndef CONFIG_SOC_IA32
+    #ifndef __ZEPHYR__
     "pop    %ebp                \n" // undo function's prelude
     #endif
     "mov    4(%esp), %edx       \n" // load nlr_buf
diff --git a/zephyr/mpconfigport.h b/zephyr/mpconfigport.h
index e1e85df9cd..ff8a593a49 100644
--- a/zephyr/mpconfigport.h
+++ b/zephyr/mpconfigport.h
@@ -27,6 +27,8 @@
 
 // Include Zephyr's autoconf.h, which should be made first by Zephyr makefiles
 #include "autoconf.h"
+// Included here to get basic Zephyr environment (macros, etc.)
+#include <zephyr.h>
 
 // Usually passed from Makefile
 #ifndef MICROPY_HEAP_SIZE