diff --git a/cpu/x86/drivers/pic.c b/cpu/x86/drivers/pic.c
index 2e6428756..12b79e39b 100644
--- a/cpu/x86/drivers/pic.c
+++ b/cpu/x86/drivers/pic.c
@@ -30,6 +30,8 @@
 
 #include "drivers/pic.h"
 
+#define PIC_ACK 0x20
+
 void
 pic_unmask_irq(unsigned int num)
 {
@@ -46,3 +48,13 @@ pic_unmask_irq(unsigned int num)
   bitmap = inb(port);
   outb(port, bitmap & ~BIT(num));
 }
+/*---------------------------------------------------------------------------*/
+void
+pic_eoi(unsigned int irq)
+{
+  if(irq >= 8) {
+    outb(PIC2_CMD_PORT, PIC_ACK);
+  }
+
+  outb(PIC1_CMD_PORT, PIC_ACK);
+}
diff --git a/cpu/x86/drivers/pic.h b/cpu/x86/drivers/pic.h
index 81de51e7b..d39942438 100644
--- a/cpu/x86/drivers/pic.h
+++ b/cpu/x86/drivers/pic.h
@@ -37,6 +37,14 @@
 #define PIC1_DATA_PORT  0x21
 #define PIC2_CMD_PORT   0xA0
 #define PIC2_DATA_PORT  0xA1
+#define PIC1_OFFSET     0x20
+#define PIC2_OFFSET     PIC1_OFFSET + 8
+
+/*
+ * Returns the actual interrupt number of a given IRQ,
+ * no matter which PIC it is part of.
+ */
+#define PIC_INT(a)      (a + PIC1_OFFSET)
 
 void pic_unmask_irq(unsigned int num);
 
@@ -52,8 +60,8 @@ pic_init(void)
   outb(PIC2_CMD_PORT, 0x11);
 
   /* ICW2: Remap IRQs by setting an IDT Offset for each PIC. */
-  outb(PIC1_DATA_PORT, 0x20);
-  outb(PIC2_DATA_PORT, 0x28);
+  outb(PIC1_DATA_PORT, PIC1_OFFSET);
+  outb(PIC2_DATA_PORT, PIC2_OFFSET);
 
   /* ICW3: Setup Slave to Master's IRQ2. */
   outb(PIC1_DATA_PORT, 0x04);
@@ -69,4 +77,10 @@ pic_init(void)
   outb(PIC2_DATA_PORT, 0xff);
 }
 
+/*
+ * This function sends an end-of-interrupt (EOI) to the correct PIC according
+ * to the IRQ line number.
+ */
+void pic_eoi(unsigned int irq);
+
 #endif /* PIC_H */
diff --git a/cpu/x86/drivers/pit.c b/cpu/x86/drivers/pit.c
index 9eeb38523..557b27985 100644
--- a/cpu/x86/drivers/pit.c
+++ b/cpu/x86/drivers/pit.c
@@ -39,6 +39,8 @@
 #define PIT_CONTROL_PORT    0x43
 #define PIT_COUNTER0_PORT   0x40
 #define PIT_CLOCK_FREQUENCY 1193182
+#define PIT_IRQ 0
+#define PIT_INT PIC_INT(PIT_IRQ)
 
 static pit_int_callback interrupt_cb;
 
@@ -47,15 +49,13 @@ pit_int_handler(void)
 {
   interrupt_cb();
 
-  /* FIXME: Add a pic_send_eoi() API or similar and call it here. */
-  outb(0x20, 0x20); /* master PIC */
+  pic_eoi(PIT_IRQ);
 }
 /*---------------------------------------------------------------------------*/
 void
 pit_init(uint32_t ticks_rate, pit_int_callback cb)
 {
-  /* FIXME: Call some PIC API to get the current offset and then add to its default IRQ number (0). */
-  SET_INTERRUPT_HANDLER(32, 0, pit_int_handler);
+  SET_INTERRUPT_HANDLER(PIT_INT, 0, pit_int_handler);
 
   interrupt_cb = cb;
 
@@ -76,5 +76,5 @@ pit_init(uint32_t ticks_rate, pit_int_callback cb)
   outb(PIT_COUNTER0_PORT, divisor & 0xFF); /* Write least significant bytes first. */
   outb(PIT_COUNTER0_PORT, (divisor >> 8) & 0xFF);
 
-  pic_unmask_irq(0);
+  pic_unmask_irq(PIT_IRQ);
 }
diff --git a/cpu/x86/drivers/rtc.c b/cpu/x86/drivers/rtc.c
index 243c6623f..ad9eec221 100644
--- a/cpu/x86/drivers/rtc.c
+++ b/cpu/x86/drivers/rtc.c
@@ -35,6 +35,8 @@
 
 #define RTC_INDEX_REGISTER   0x70
 #define RTC_TARGET_REGISTER  0x71
+#define RTC_IRQ 8
+#define RTC_INT PIC_INT(RTC_IRQ)
 
 static void (*user_callback)(void);
 
@@ -51,8 +53,7 @@ rtc_handler()
   inb(RTC_TARGET_REGISTER);
 
   /* Issue the End of Interrupt to PIC */
-  outb(0xA0, 0x20);
-  outb(0x20, 0x20);
+  pic_eoi(RTC_IRQ);
 }
 /*---------------------------------------------------------------------------*/
 /* Initialize the Real Time Clock.
@@ -69,10 +70,7 @@ rtc_init(rtc_frequency_t frequency, void (*callback)(void))
 
   user_callback = callback;
 
-  /* FIXME: Once we have a proper API to ask PIC what is the IRQ offset, we
-   * should consider using it here.
-   */
-  SET_INTERRUPT_HANDLER(40, 0, rtc_handler);
+  SET_INTERRUPT_HANDLER(RTC_INT, 0, rtc_handler);
 
   /* Select interrupt period to 7.8125 ms */
   outb(RTC_INDEX_REGISTER, 0x0A);
@@ -88,5 +86,5 @@ rtc_init(rtc_frequency_t frequency, void (*callback)(void))
   outb(RTC_INDEX_REGISTER, 0x0B);
   outb(RTC_TARGET_REGISTER, reg_b | BIT(6));
 
-  pic_unmask_irq(8);
+  pic_unmask_irq(RTC_IRQ);
 }