diff --git a/drivers/pinmux/stm32/pinmux_stm32.h b/drivers/pinmux/stm32/pinmux_stm32.h
index 620264fd1fc..9a7aed4d184 100644
--- a/drivers/pinmux/stm32/pinmux_stm32.h
+++ b/drivers/pinmux/stm32/pinmux_stm32.h
@@ -314,4 +314,8 @@ void stm32_setup_pins(const struct pin_config *pinconf,
 #include "pinmux_stm32f4.h"
 #endif
 
+#ifdef CONFIG_SOC_SERIES_STM32L4X
+#include "pinmux_stm32l4x.h"
+#endif
+
 #endif	/* _STM32_PINMUX_H_ */
diff --git a/drivers/pinmux/stm32/pinmux_stm32l4x.h b/drivers/pinmux/stm32/pinmux_stm32l4x.h
new file mode 100644
index 00000000000..f2af956393c
--- /dev/null
+++ b/drivers/pinmux/stm32/pinmux_stm32l4x.h
@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2016 Open-RnD Sp. z o.o.
+ * Copyright (c) 2016 BayLibre, SAS
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef _STM32L4X_PINMUX_H_
+#define _STM32L4X_PINMUX_H_
+
+/**
+ * @file Header for STM32L4X pin multiplexing helper
+ */
+
+#define STM32L4X_PINMUX_FUNC_PA9_USART1_TX STM32_PINMUX_FUNC_ALT_7
+#define STM32L4X_PINMUX_FUNC_PA10_USART1_RX STM32_PINMUX_FUNC_ALT_7
+
+#define STM32L4X_PINMUX_FUNC_PA2_USART2_TX STM32_PINMUX_FUNC_ALT_7
+#define STM32L4X_PINMUX_FUNC_PA3_USART2_RX STM32_PINMUX_FUNC_ALT_7
+
+#define STM32L4X_PINMUX_FUNC_PB6_USART3_TX STM32_PINMUX_FUNC_ALT_7
+#define STM32L4X_PINMUX_FUNC_PB7_USART3_RX STM32_PINMUX_FUNC_ALT_7
+
+#define STM32L4X_PINMUX_FUNC_PB10_USART3_TX STM32_PINMUX_FUNC_ALT_7
+#define STM32L4X_PINMUX_FUNC_PB11_USART3_RX STM32_PINMUX_FUNC_ALT_7
+
+#define STM32L4X_PINMUX_FUNC_PC4_USART3_TX STM32_PINMUX_FUNC_ALT_7
+#define STM32L4X_PINMUX_FUNC_PC5_USART3_RX STM32_PINMUX_FUNC_ALT_7
+
+#define STM32L4X_PINMUX_FUNC_PC10_USART3_TX STM32_PINMUX_FUNC_ALT_7
+#define STM32L4X_PINMUX_FUNC_PC11_USART3_RX STM32_PINMUX_FUNC_ALT_7
+
+#define STM32L4X_PINMUX_FUNC_PD5_USART2_TX STM32_PINMUX_FUNC_ALT_7
+#define STM32L4X_PINMUX_FUNC_PD6_USART2_RX STM32_PINMUX_FUNC_ALT_7
+
+#define STM32L4X_PINMUX_FUNC_PD5_USART2_TX STM32_PINMUX_FUNC_ALT_7
+#define STM32L4X_PINMUX_FUNC_PD6_USART2_RX STM32_PINMUX_FUNC_ALT_7
+
+#define STM32L4X_PINMUX_FUNC_PD8_USART3_TX STM32_PINMUX_FUNC_ALT_7
+#define STM32L4X_PINMUX_FUNC_PD9_USART3_RX STM32_PINMUX_FUNC_ALT_7
+
+#define STM32L4X_PINMUX_FUNC_PG9_USART1_TX STM32_PINMUX_FUNC_ALT_7
+#define STM32L4X_PINMUX_FUNC_PG10_USART1_RX STM32_PINMUX_FUNC_ALT_7
+
+#endif /* _STM32L4X_PINMUX_H_ */