diff --git a/boards/arm/lc823450/lc823450-xgevk/configs/bt/defconfig b/boards/arm/lc823450/lc823450-xgevk/configs/bt/defconfig
index 609309ab9fc..e78036efc4f 100644
--- a/boards/arm/lc823450/lc823450-xgevk/configs/bt/defconfig
+++ b/boards/arm/lc823450/lc823450-xgevk/configs/bt/defconfig
@@ -69,7 +69,6 @@ CONFIG_LC823450_UART1=y
 CONFIG_LC823450_XGEVK_BTPOWER=y
 CONFIG_LCD=y
 CONFIG_LCD_ST7565=y
-CONFIG_LIBC_IOCTL_VARIADIC=y
 CONFIG_LIBM=y
 CONFIG_LIB_KBDCODEC=y
 CONFIG_MAX_TASKS=64
diff --git a/boards/arm/lpc17xx_40xx/lx_cpu/configs/nsh/defconfig b/boards/arm/lpc17xx_40xx/lx_cpu/configs/nsh/defconfig
index 641defb3446..7a82c868f47 100644
--- a/boards/arm/lpc17xx_40xx/lx_cpu/configs/nsh/defconfig
+++ b/boards/arm/lpc17xx_40xx/lx_cpu/configs/nsh/defconfig
@@ -66,7 +66,6 @@ CONFIG_FS_UNIONFS=y
 CONFIG_I2C=y
 CONFIG_INTELHEX_BINARY=y
 CONFIG_LIBC_DLFCN=y
-CONFIG_LIBC_IOCTL_VARIADIC=y
 CONFIG_LIBC_STRERROR=y
 CONFIG_LIB_ENVPATH=y
 CONFIG_LPC17_40_CAN2=y
diff --git a/boards/sim/sim/sim/configs/tcpblaster/defconfig b/boards/sim/sim/sim/configs/tcpblaster/defconfig
index 2939dd071ce..5f9f4c82d2e 100644
--- a/boards/sim/sim/sim/configs/tcpblaster/defconfig
+++ b/boards/sim/sim/sim/configs/tcpblaster/defconfig
@@ -36,7 +36,6 @@ CONFIG_IOB_NCHAINS=128
 CONFIG_IOB_NOTIFIER=y
 CONFIG_IOB_THROTTLE=16
 CONFIG_LIBC_EXECFUNCS=y
-CONFIG_LIBC_IOCTL_VARIADIC=y
 CONFIG_LIBC_LOCALE=y
 CONFIG_LIBC_LOCALTIME=y
 CONFIG_LIBM=y
diff --git a/libs/libc/misc/Kconfig b/libs/libc/misc/Kconfig
index fce6ab36f13..7247e91da7b 100644
--- a/libs/libc/misc/Kconfig
+++ b/libs/libc/misc/Kconfig
@@ -5,7 +5,7 @@
 
 config LIBC_IOCTL_VARIADIC
 	bool "Enable variadic ioctl()"
-	default n
+	default y
 	---help---
 		By default, NuttX implements the "old style," three-parameter,
 		ioctl() interface with this function prototype: