diff --git a/core/embed/firmware/main.c b/core/embed/firmware/main.c
index f6f032bfa..0e6d58e44 100644
--- a/core/embed/firmware/main.c
+++ b/core/embed/firmware/main.c
@@ -53,8 +53,6 @@
 extern void shutdown_privileged(void);
 
 int main(void) {
-  random_delays_init();
-
 #ifdef RDI
   rdi_start();
 #endif
diff --git a/core/embed/firmware/startup.S b/core/embed/firmware/startup.S
index a64bbf650..a0f3fb0d8 100644
--- a/core/embed/firmware/startup.S
+++ b/core/embed/firmware/startup.S
@@ -11,6 +11,7 @@ reset_handler:
 // (cf mpu_config_firmware in legacy bootloader)
 
 #if TREZOR_MODEL == 1
+  cpsid if
   ldr r0, =0xE000ED08  // r0 = VTOR address
   ldr r1, =0x08010400  // r1 = FLASH_APP_START
   str r1, [r0]         // assign
@@ -43,11 +44,19 @@ reset_handler:
   ldr r1, = __stack_chk_guard
   str r0, [r1]
 
+#ifdef RDI
+  bl random_delays_init
+#endif
+
   // re-enable exceptions
   // according to "ARM Cortex-M Programming Guide to Memory Barrier Instructions" Application Note 321, section 4.7:
   // "If it is not necessary to ensure that a pended interrupt is recognized immediately before
   // subsequent operations, it is not necessary to insert a memory barrier instruction."
+#if TREZOR_MODEL == T
   cpsie f
+#elif TREZOR_MODEL == 1
+  cpsie if
+#endif
 
   // enter the application code
   bl main