diff --git a/include/libopencm3/stm32/l4/syscfg.h b/include/libopencm3/stm32/l4/syscfg.h
new file mode 100644
index 00000000..934d7ac5
--- /dev/null
+++ b/include/libopencm3/stm32/l4/syscfg.h
@@ -0,0 +1,121 @@
+/** @defgroup syscfg_defines SYSCFG Defines
+ *
+ * @ingroup STM32L4xx_defines
+ *
+ * @brief Defined Constants and Types for the STM32L4xx Sysconfig
+ *
+ * @version 1.0.0
+ *
+ * @date 28 December 2017
+ *
+ * LGPL License Terms @ref lgpl_license
+ */
+
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * Copyright (C) Bruno Randolf <br1@einfach.org>
+ *
+ * This library is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef LIBOPENCM3_SYSCFG_H
+#define LIBOPENCM3_SYSCFG_H
+/**@{*/
+
+/* --- SYSCFG registers ---------------------------------------------------- */
+
+#define SYSCFG_MEMRMP			MMIO32(SYSCFG_BASE + 0x00)
+#define SYSCFG_CFGR1			MMIO32(SYSCFG_BASE + 0x04)
+#define SYSCFG_EXTICR(i)		MMIO32(SYSCFG_BASE + 0x08 + (i)*4)
+#define SYSCFG_EXTICR1			SYSCFG_EXTICR(0)
+#define SYSCFG_EXTICR2			SYSCFG_EXTICR(1)
+#define SYSCFG_EXTICR3			SYSCFG_EXTICR(2)
+#define SYSCFG_EXTICR4			SYSCFG_EXTICR(3)
+#define SYSCFG_SCSR			MMIO32(SYSCFG_BASE + 0x18)
+#define SYSCFG_CFGR2			MMIO32(SYSCFG_BASE + 0x1C)
+#define SYSCFG_SWPR			MMIO32(SYSCFG_BASE + 0x20)
+#define SYSCFG_SKR			MMIO32(SYSCFG_BASE + 0x24)
+#define SYSCFG_SWPR2			MMIO32(SYSCFG_BASE + 0x29)
+
+/* --- SYSCFG_MEMRMP Values ------------------------------------------------ */
+
+#define SYSCFG_MEMRMP_MEM_MODE_MASK	7
+#define SYSCFG_MEMRMP_MEM_MODE_FLASH	0
+#define SYSCFG_MEMRMP_MEM_MODE_SYSTEM	1
+#define SYSCFG_MEMRMP_MEM_MODE_FMC	2
+#define SYSCFG_MEMRMP_MEM_MODE_SRAM	3
+#define SYSCFG_MEMRMP_MEM_MODE_QSPI	6
+
+/* --- SYSCFG_CFGR1 Values ------------------------------------------------- */
+
+#define SYSCFG_CFGR1_FPU_IE_INEXACT	(1 << 31)
+#define SYSCFG_CFGR1_FPU_IE_DENORMAL	(1 << 30)
+#define SYSCFG_CFGR1_FPU_IE_OVERFLOW	(1 << 29)
+#define SYSCFG_CFGR1_FPU_IE_UNDERFLOW	(1 << 28)
+#define SYSCFG_CFGR1_FPU_IE_DIVZERO	(1 << 27)
+#define SYSCFG_CFGR1_FPU_IE_INVALID	(1 << 26)
+
+#define SYSCFG_CFGR1_I2C3_FMP		(1 << 22)
+#define SYSCFG_CFGR1_I2C2_FMP		(1 << 21)
+#define SYSCFG_CFGR1_I2C1_FMP		(1 << 20)
+
+#define SYSCFG_CFGR1_I2C_PB9_FMP	(1 << 19)
+#define SYSCFG_CFGR1_I2C_PB8_FMP	(1 << 18)
+#define SYSCFG_CFGR1_I2C_PB7_FMP	(1 << 17)
+#define SYSCFG_CFGR1_I2C_PB6_FMP	(1 << 16)
+
+#define SYSCFG_CFGR1_BOOSTEN		(1 << 8)
+#define SYSCFG_CFGR1_FWDIS		(1 << 0)
+
+/* --- SYSCFG_EXTICR Values -------------------------------------------------*/
+
+#define SYSCFG_EXTICR_GPIOA		0
+#define SYSCFG_EXTICR_GPIOB		1
+#define SYSCFG_EXTICR_GPIOC		2
+#define SYSCFG_EXTICR_GPIOD		3
+#define SYSCFG_EXTICR_GPIOE		4
+#define SYSCFG_EXTICR_GPIOH		7
+
+/* --- SYSCFG_SCSR Values -------------------------------------------------- */
+
+#define SYSCFG_SCSR_SRAM2BSY		(1 << 1)
+#define SYSCFG_SCSR_SRAM2ER		(1 << 0)
+
+/* --- SYSCFG_CFGR2 Values ------------------------------------------------- */
+
+#define SYSCFG_CFGR2_SPF		(1 << 8)
+#define SYSCFG_CFGR2_ECCL		(1 << 3)
+#define SYSCFG_CFGR2_PVDL		(1 << 2)
+#define SYSCFG_CFGR2_SPL		(1 << 1)
+#define SYSCFG_CFGR2_CCL		(1 << 0)
+
+/* --- SYSCFG_SWPR Values -------------------------------------------------- */
+
+/* 0 - 15 or 0 - 32 depending on L4 version */
+#define SYSCFG_SWPR_PxWP(x)		(1 << x)
+
+/* --- SYSCFG_SKR Values --------------------------------------------------- */
+
+#define SYSCFG_SKR_KEY1			0xCA
+#define SYSCFG_SKR_KEY2			0x53
+
+/* --- SYSCFG_SWPR2 Values -------------------------------------------------- */
+
+/* 32 - 63 or not available depending on L4 version */
+#define SYSCFG_SWPR2_PxWP(x)		(1 << (x - 32))
+
+/**@}*/
+
+#endif
diff --git a/include/libopencm3/stm32/syscfg.h b/include/libopencm3/stm32/syscfg.h
index 503556f1..b5fc0e47 100644
--- a/include/libopencm3/stm32/syscfg.h
+++ b/include/libopencm3/stm32/syscfg.h
@@ -32,6 +32,8 @@
 #       include <libopencm3/stm32/l0/syscfg.h>
 #elif defined(STM32L1)
 #       include <libopencm3/stm32/l1/syscfg.h>
+#elif defined(STM32L4)
+#       include <libopencm3/stm32/l4/syscfg.h>
 #else
 #       error "stm32 family not defined."
 #endif