diff --git a/arch/arm/core/cortex_m/reset.S b/arch/arm/core/cortex_m/reset.S
index dedb5f0982f..564d0a2c1a9 100644
--- a/arch/arm/core/cortex_m/reset.S
+++ b/arch/arm/core/cortex_m/reset.S
@@ -33,6 +33,7 @@
 _ASM_FILE_PROLOGUE
 
 GTEXT(__reset)
+GTEXT(memset)
 GDATA(_interrupt_stack)
 
 /**
@@ -78,6 +79,13 @@ SECTION_SUBSEC_FUNC(TEXT,_reset_section,__start)
     msr BASEPRI, r0
 #endif
 
+#ifdef CONFIG_INIT_STACKS
+    ldr r0, =_interrupt_stack
+    mov r1, #0xaa
+    ldr r2, =CONFIG_ISR_STACK_SIZE
+    bl memset
+#endif
+
     /*
      * Set PSP and use it to boot without using MSP, so that it
      * gets set to _interrupt_stack during nanoInit().
diff --git a/arch/arm/core/cortex_m/vector_table.S b/arch/arm/core/cortex_m/vector_table.S
index 240b3a07c76..c9f725ba743 100644
--- a/arch/arm/core/cortex_m/vector_table.S
+++ b/arch/arm/core/cortex_m/vector_table.S
@@ -36,6 +36,8 @@
 
 _ASM_FILE_PROLOGUE
 
+GDATA(_main_stack)
+
 SECTION_SUBSEC_FUNC(exc_vector_table,_vector_table_section,_vector_table)
 
 /* in XIP kernels. the entry point is also the start of the vector table */
@@ -43,7 +45,13 @@ SECTION_SUBSEC_FUNC(exc_vector_table,_vector_table_section,_vector_table)
 SECTION_SUBSEC_FUNC(exc_vector_table,_vector_table_section,__start)
 #endif
 
-    .word 0 /* no need for a stack, the kernel sets one up before running C */
+    /*
+     * setting the _very_ early boot on the main stack allows to use memset
+     * on the interrupt stack when CONFIG_INIT_STACKS is enabled before
+     * switching to the interrupt stack for the rest of the early boot
+     */
+    .word _main_stack + CONFIG_MAIN_STACK_SIZE
+
     .word __reset
     .word __nmi