diff --git a/target/linux/ifxmips/files/arch/mips/ifxmips/prom.c b/target/linux/ifxmips/files/arch/mips/ifxmips/prom.c
index a0fc68ebd6..9fbd4e457e 100644
--- a/target/linux/ifxmips/files/arch/mips/ifxmips/prom.c
+++ b/target/linux/ifxmips/files/arch/mips/ifxmips/prom.c
@@ -32,7 +32,7 @@ unsigned int prom_cp1_size;
 /* for Multithreading (APRP) on MIPS34K */
 unsigned long physical_memsize;
 
-#ifdef IFXMIPS_PROM_ASC0
+#ifdef CONFIG_IFXMIPS_PROM_ASC0
 #define IFXMIPS_ASC_DIFF	0
 #else
 #define IFXMIPS_ASC_DIFF	IFXMIPS_ASC_BASE_DIFF