diff --git a/targets/TARGET_STM/TARGET_STM32L5/TARGET_STM32L552xE/TARGET_NUCLEO_L552ZE_Q/PinNames.h b/targets/TARGET_STM/TARGET_STM32L5/TARGET_STM32L552xE/TARGET_NUCLEO_L552ZE_Q/PinNames.h
index 69d8424d23..db055cde1e 100644
--- a/targets/TARGET_STM/TARGET_STM32L5/TARGET_STM32L552xE/TARGET_NUCLEO_L552ZE_Q/PinNames.h
+++ b/targets/TARGET_STM/TARGET_STM32L5/TARGET_STM32L552xE/TARGET_NUCLEO_L552ZE_Q/PinNames.h
@@ -2,7 +2,7 @@
  * SPDX-License-Identifier: BSD-3-Clause
  ******************************************************************************
  *
- * Copyright (c) 2016-2020 STMicroelectronics.
+ * Copyright (c) 2016-2021 STMicroelectronics.
  * All rights reserved.
  *
  * This software component is licensed by ST under BSD 3-Clause license,
@@ -31,12 +31,9 @@ typedef enum {
     ALT0  = 0x100,
     ALT1  = 0x200,
     ALT2  = 0x300,
-    ALT3  = 0x400,
-    ALT4  = 0x500
 } ALTx;
 
 typedef enum {
-
     PA_0       = 0x00,
     PA_0_ALT0  = PA_0  | ALT0, // same pin used for alternate HW
     PA_1       = 0x01,
@@ -195,12 +192,14 @@ typedef enum {
     ADC_VBAT = 0xF2, // Internal pin virtual value
 
 #ifdef TARGET_FF_ARDUINO_UNO
+    // Arduino Uno (Rev3) pins
     ARDUINO_UNO_A0  = PA_3,
     ARDUINO_UNO_A1  = PA_2,
     ARDUINO_UNO_A2  = PC_3,
     ARDUINO_UNO_A3  = PB_0,
     ARDUINO_UNO_A4  = PC_1,
     ARDUINO_UNO_A5  = PC_0,
+
     ARDUINO_UNO_D0  = PD_9,
     ARDUINO_UNO_D1  = PD_8,
     ARDUINO_UNO_D2  = PF_15,
@@ -275,7 +274,6 @@ typedef enum {
 #define LED3     PA_9   // LD3 Red
 #define BUTTON1  PC_13
 
-
 #ifdef __cplusplus
 }
 #endif
diff --git a/targets/TARGET_STM/TARGET_STM32L5/TARGET_STM32L562xE/TARGET_DISCO_L562QE/PinNames.h b/targets/TARGET_STM/TARGET_STM32L5/TARGET_STM32L562xE/TARGET_DISCO_L562QE/PinNames.h
index 6e35d8de58..d780f773d4 100644
--- a/targets/TARGET_STM/TARGET_STM32L5/TARGET_STM32L562xE/TARGET_DISCO_L562QE/PinNames.h
+++ b/targets/TARGET_STM/TARGET_STM32L5/TARGET_STM32L562xE/TARGET_DISCO_L562QE/PinNames.h
@@ -2,7 +2,7 @@
  * SPDX-License-Identifier: BSD-3-Clause
  ******************************************************************************
  *
- * Copyright (c) 2016-2020 STMicroelectronics.
+ * Copyright (c) 2016-2021 STMicroelectronics.
  * All rights reserved.
  *
  * This software component is licensed by ST under BSD 3-Clause license,
@@ -31,12 +31,9 @@ typedef enum {
     ALT0  = 0x100,
     ALT1  = 0x200,
     ALT2  = 0x300,
-    ALT3  = 0x400,
-    ALT4  = 0x500
 } ALTx;
 
 typedef enum {
-
     PA_0       = 0x00,
     PA_0_ALT0  = PA_0  | ALT0, // same pin used for alternate HW
     PA_1       = 0x01,
@@ -192,12 +189,14 @@ typedef enum {
     ADC_VBAT = 0xF2, // Internal pin virtual value
 
 #ifdef TARGET_FF_ARDUINO_UNO
+    // Arduino Uno (Rev3) pins
     ARDUINO_UNO_A0  = PA_0,
     ARDUINO_UNO_A1  = PA_1,
     ARDUINO_UNO_A2  = PA_4,
     ARDUINO_UNO_A3  = PA_5,
     ARDUINO_UNO_A4  = PC_4,
     ARDUINO_UNO_A5  = PC_5,
+
     ARDUINO_UNO_D0  = PB_10,
     ARDUINO_UNO_D1  = PB_11,
     ARDUINO_UNO_D2  = PD_11,
@@ -332,7 +331,7 @@ typedef enum {
 // Standardized LED and button names
 #define LED1     PG_12  // LD7 Green
 #define LED2     PE_1   // LD9 Red
-#define BUTTON1  PC_13
+#define BUTTON1  PC_13  // USER_BUTTON
 
 #ifdef __cplusplus
 }