diff --git a/configs/sifive_unmatched_defconfig b/configs/sifive_unmatched_defconfig
index dddc25c..cbada15 100644
--- a/configs/sifive_unmatched_defconfig
+++ b/configs/sifive_unmatched_defconfig
@@ -10,6 +10,7 @@
 CONFIG_SPL=y
 CONFIG_SPL_SPI_FLASH_SUPPORT=y
 CONFIG_SPL_SPI=y
+CONFIG_SYS_PCI_64BIT=y
 CONFIG_AHCI=y
 CONFIG_TARGET_SIFIVE_UNMATCHED=y
 CONFIG_ARCH_RV64I=y