diff --git a/arch/sparc/core/interrupt_trap.S b/arch/sparc/core/interrupt_trap.S
index 78304123dd..20c1800dce 100644
--- a/arch/sparc/core/interrupt_trap.S
+++ b/arch/sparc/core/interrupt_trap.S
@@ -86,12 +86,12 @@ __sparc_trap_interrupt:
 	 * task is restored.
 	 */
 
-	/* Allocate stack for isr context including ABI frame. */
+	/* Allocate stack for isr context. */
 	sub	%fp, ISF_SIZE, %sp
 	/*
 	 * %fp: %sp of interrupted task
 	 * %sp: %sp of interrupted task - ISF_SIZE.
-	 *      (fits a full ABI frame + what we store here)
+	 *      (fits what we store here)
 	 *
 	 * Save the interrupted context.
 	 */
diff --git a/arch/sparc/core/stack_offsets.h b/arch/sparc/core/stack_offsets.h
index 0692fe1d44..0c32e3cfc6 100644
--- a/arch/sparc/core/stack_offsets.h
+++ b/arch/sparc/core/stack_offsets.h
@@ -41,15 +41,24 @@
 
 
 /* Interrupt stack frame */
-#define ISF_PSR_OFFSET  (STACK_FRAME_SIZE + 0x00)
-#define ISF_PC_OFFSET   (STACK_FRAME_SIZE + 0x04)
-#define ISF_NPC_OFFSET  (STACK_FRAME_SIZE + 0x08)
-#define ISF_G1_OFFSET   (STACK_FRAME_SIZE + 0x0c)
-#define ISF_G2_OFFSET   (STACK_FRAME_SIZE + 0x10)
-#define ISF_G3_OFFSET   (STACK_FRAME_SIZE + 0x14)
-#define ISF_G4_OFFSET   (STACK_FRAME_SIZE + 0x18)
-#define ISF_Y_OFFSET    (STACK_FRAME_SIZE + 0x1c)
+#define ISF_PSR_OFFSET  (0x40 + 0x00)
+#define ISF_PC_OFFSET   (0x40 + 0x04)
+#define ISF_NPC_OFFSET  (0x40 + 0x08)
+#define ISF_G1_OFFSET   (0x40 + 0x0c)
+#define ISF_G2_OFFSET   (0x40 + 0x10)
+#define ISF_G3_OFFSET   (0x40 + 0x14)
+#define ISF_G4_OFFSET   (0x40 + 0x18)
+#define ISF_Y_OFFSET    (0x40 + 0x1c)
 
-#define ISF_SIZE        (STACK_FRAME_SIZE + 0x20)
+#if !defined(_FLAT)
+ #define ISF_SIZE       (0x20)
+#else
+/*
+ * The flat ABI stores and loads "local" and "in" registers in the save area as
+ * part of function prologue and epilogue. So we allocate space for a new save
+ * area (0x40 byte) as part of the interrupt stack frame.
+ */
+ #define ISF_SIZE       (0x40 + 0x20)
+#endif
 
 #endif /* ZEPHYR_ARCH_SPARC_CORE_STACK_H_ */