diff --git a/sys/arm/arm/gic.c b/sys/arm/arm/gic.c
index a138d2d1c91..9e15f8bc285 100644
--- a/sys/arm/arm/gic.c
+++ b/sys/arm/arm/gic.c
@@ -83,7 +83,11 @@ __FBSDID("$FreeBSD$");
 #define GICC_ABPR		0x001C			/* v1 ICCABPR */
 #define GICC_IIDR		0x00FC			/* v1 ICCIIDR*/
 
-#define	GIC_LAST_IPI		15	/* Irqs 0-15 are IPIs. */
+#define	GIC_FIRST_IPI		 0	/* Irqs 0-15 are SGIs/IPIs. */
+#define	GIC_LAST_IPI		15
+#define	GIC_FIRST_PPI		16	/* Irqs 16-31 are private (per */
+#define	GIC_LAST_PPI		31	/* core) peripheral interrupts. */
+#define	GIC_FIRST_SPI		32	/* Irqs 32+ are shared peripherals. */
 
 /* First bit is a polarity bit (0 - low, 1 - high) */
 #define GICD_ICFGR_POL_LOW	(0 << 0)
@@ -205,9 +209,9 @@ gic_decode_fdt(uint32_t iparent, uint32_t *intr, int *interrupt,
 		*pol = INTR_POLARITY_CONFORM;
 	} else {
 		if (intr[0] == 0)
-			*interrupt = fdt32_to_cpu(intr[1]) + 32;
+			*interrupt = fdt32_to_cpu(intr[1]) + GIC_FIRST_SPI;
 		else
-			*interrupt = fdt32_to_cpu(intr[1]);
+			*interrupt = fdt32_to_cpu(intr[1]) + GIC_FIRST_PPI;
 		/*
 		 * In intr[2], bits[3:0] are trigger type and level flags.
 		 *   1 = low-to-high edge triggered