diff --git a/reactos/hal/halx86/hal_generic_acpi.rbuild b/reactos/hal/halx86/hal_generic_acpi.rbuild
index 97501cb1823..babc0e8dfd1 100644
--- a/reactos/hal/halx86/hal_generic_acpi.rbuild
+++ b/reactos/hal/halx86/hal_generic_acpi.rbuild
@@ -6,6 +6,7 @@
 		<include base="ntoskrnl">include</include>
 		<define name="_NTHALDLL_" />
 		<define name="_NTHAL_" />
+		<define name="CONFIG_ACPI" />
 		<directory name="generic">
     	    <directory name="acpi">
     	        <file>halacpi.c</file>
diff --git a/reactos/hal/halx86/halacpi.rbuild b/reactos/hal/halx86/halacpi.rbuild
index d380cf6889e..2037d9f759d 100644
--- a/reactos/hal/halx86/halacpi.rbuild
+++ b/reactos/hal/halx86/halacpi.rbuild
@@ -8,6 +8,7 @@
 		<include base="ntoskrnl">include</include>
 		<define name="_NTHALDLL_" />
 		<define name="_NTHAL_" />
+		<define name="CONFIG_ACPI" />
 		<library>hal_generic</library>
 		<library>hal_generic_acpi</library>
 		<library>hal_generic_up</library>