diff --git a/os/ports/GCC/PPC/ivor.s b/os/ports/GCC/PPC/ivor.s
index 46dc66bf5..8235af0e5 100644
--- a/os/ports/GCC/PPC/ivor.s
+++ b/os/ports/GCC/PPC/ivor.s
@@ -86,6 +86,11 @@ _IVOR10:
         lis         %r3, 0x0800             /* DIS bit mask.                */
         mtspr       336, %r3                /* TSR register.                */
 
+#if PPC_USE_IRQ_PREEMPTION
+        /* Allows preemption while executing the software handler.*/
+        wrteei      1
+#endif
+
 #if CH_DBG_SYSTEM_STATE_CHECK
         bl          dbg_check_enter_isr
         bl          dbg_check_lock_from_isr
@@ -96,6 +101,11 @@ _IVOR10:
         bl          dbg_check_leave_isr
 #endif
 
+#if PPC_USE_IRQ_PREEMPTION
+        /* Prevents preemption again.*/
+        wrteei      0
+#endif
+
         /* System tick handler invocation.*/
 #if CH_DBG_SYSTEM_STATE_CHECK
         bl          dbg_check_lock