diff --git a/include/linux/dmar.h b/include/linux/dmar.h
index a8b1a847c103bb5cefed7aa7dbb6f4f847079fd5..731a60975101ce76c8e6aa045acde8409c0c2059 100644
--- a/include/linux/dmar.h
+++ b/include/linux/dmar.h
@@ -26,6 +26,8 @@
 #include <linux/msi.h>
 #include <linux/irqreturn.h>
 
+struct acpi_dmar_header;
+
 /* DMAR Flags */
 #define DMAR_INTR_REMAP		0x1
 #define DMAR_X2APIC_OPT_OUT	0x2