diff --git a/kernel/arch/i386/apic.c b/kernel/arch/i386/apic.c
index 32b6d8bb7..b5fa1a26f 100644
--- a/kernel/arch/i386/apic.c
+++ b/kernel/arch/i386/apic.c
@@ -144,7 +144,9 @@ PUBLIC void apic_calibrate_clocks(void)
 	init_8253A_timer(system_hz);
 
 	/* loop for some time to get a sample */
-	while(probe_ticks < PROBE_TICKS);
+	while(probe_ticks < PROBE_TICKS) {
+		intr_enable();
+	}
 
 	intr_disable();
 	stop_8253A_timer();
diff --git a/kernel/arch/i386/apic_asm.S b/kernel/arch/i386/apic_asm.S
index 815ce2825..d014928e9 100644
--- a/kernel/arch/i386/apic_asm.S
+++ b/kernel/arch/i386/apic_asm.S
@@ -48,6 +48,7 @@
 	pusha								;\
 	call	cycles_accounting_stop_idle				;\
 	APIC_IRQ_HANDLER(irq)						;\
+	CLEAR_IF(10*4(%esp))						;\
 	popa								;\
 	iret								;
 
@@ -158,6 +159,7 @@ apic_hwint15:
 	pusha								;\
 	call	cycles_accounting_stop_idle				;\
 	LAPIC_INTR_HANDLER(func)					;\
+	CLEAR_IF(10*4(%esp))						;\
 	popa								;\
 	iret								;
 
diff --git a/kernel/arch/i386/klib386.S b/kernel/arch/i386/klib386.S
index d1bb9c1aa..a4b09c005 100644
--- a/kernel/arch/i386/klib386.S
+++ b/kernel/arch/i386/klib386.S
@@ -608,8 +608,11 @@ idt_zero:
  */
 halt_cpu:
 	sti
-	hlt
-	cli
+	hlt /* interrupts enabled only after this instruction is executed! */
+	/*
+	 * interrupt handlers make sure that the interrupts are disabled when we
+	 * get here so we take only _one_ interrupt after halting the CPU
+	 */
 	ret
 
 /*===========================================================================*/
diff --git a/kernel/arch/i386/mpx386.S b/kernel/arch/i386/mpx386.S
index 293f1df02..a768db586 100644
--- a/kernel/arch/i386/mpx386.S
+++ b/kernel/arch/i386/mpx386.S
@@ -267,6 +267,7 @@ csinit:
 	PIC_IRQ_HANDLER(irq)						;\
 	movb	$END_OF_INT, %al					;\
 	outb	$INT_CTL	/* reenable interrupts in master pic */	;\
+	CLEAR_IF(10*4(%esp))						;\
 	popa								;\
 	iret								;
 
@@ -336,6 +337,7 @@ hwint07:
 	movb	$END_OF_INT, %al					;\
 	outb	$INT_CTL	/* reenable interrupts in master pic */	;\
 	outb	$INT2_CTL	/* reenable slave 8259		  */	;\
+	CLEAR_IF(10*4(%esp))						;\
 	popa								;\
 	iret								;
 
diff --git a/kernel/arch/i386/sconst.h b/kernel/arch/i386/sconst.h
index efda211d0..0bad53dd6 100644
--- a/kernel/arch/i386/sconst.h
+++ b/kernel/arch/i386/sconst.h
@@ -141,4 +141,13 @@
 	call	lazy_fpu					;\
 	add	$4, %esp					;
 
+/*
+ * clear the IF flag in eflags which are stored somewhere in memory, e.g. on
+ * stack. iret or popf will load the new value later
+ */
+#define CLEAR_IF(where)	\
+	mov	where, %eax						;\
+	andl	$0xfffffdff, %eax					;\
+	mov	%eax, where						;
+
 #endif /* __SCONST_H__ */