diff --git a/configs/sim/nxffs/defconfig b/configs/sim/nxffs/defconfig
index 2fa2297c195..15560befe09 100644
--- a/configs/sim/nxffs/defconfig
+++ b/configs/sim/nxffs/defconfig
@@ -362,6 +362,7 @@ CONFIG_NXFSS_PREALLOCATED=y
 CONFIG_RAMMTD_BLOCKSIZE=512
 CONFIG_RAMMTD_ERASESIZE=4096
 CONFIG_RAMMTD_ERASESTATE=0xff
+CONFIG_RAMMTD_FLASHSIM=y
 CONFIG_EXAMPLES_NXFFS_NEBLOCKS=32
 
 #