diff --git a/teensy/main.c b/teensy/main.c
index 41e445cb59..890ee81493 100644
--- a/teensy/main.c
+++ b/teensy/main.c
@@ -302,7 +302,7 @@ soft_reset:
 #endif
 
 #if MICROPY_MODULE_FROZEN
-    pyexec_frozen_module("boot");
+    pyexec_frozen_module("boot.py");
 #else
     if (!pyexec_file("/boot.py")) {
         flash_error(4);
@@ -314,7 +314,7 @@ soft_reset:
 
     // run main script
 #if MICROPY_MODULE_FROZEN
-    pyexec_frozen_module("main");
+    pyexec_frozen_module("main.py");
 #else
     {
         vstr_t *vstr = vstr_new();
diff --git a/teensy/memzip_files/main.py b/teensy/memzip_files/main.py
index 4f30f2fc5f..b652377f97 100644
--- a/teensy/memzip_files/main.py
+++ b/teensy/memzip_files/main.py
@@ -1,3 +1,5 @@
+import pyb
+
 print("Executing main.py")
 
 led = pyb.LED(1)