diff --git a/README.md b/README.md
index 27e9fa4..40abd80 100644
--- a/README.md
+++ b/README.md
@@ -105,6 +105,7 @@ This procedure was unfortunately not used for the SAMD51 and NRF52840 below.
 #### Family list
 
 * Microchip (Atmel) SAMD21 - 0x68ed2b88
+* Microchip (Atmel) SAML21 - 0x1851780a
 * Microchip (Atmel) SAMD51 - 0x55114460
 * Nordic NRF52840 - 0xada52840
 * ST STM32F103 - 0x5ee21072
diff --git a/patcher/patcher.js b/patcher/patcher.js
index 3de4453..dd5ea93 100644
--- a/patcher/patcher.js
+++ b/patcher/patcher.js
@@ -352,6 +352,7 @@ const enums = {
     },
     UF2_FAMILY: {
         ATSAMD21: 0x68ed2b88,
+        ATSAML21: 0x1851780a,
         ATSAMD51: 0x55114460,
         NRF52840: 0x1b57745f,
         STM32F103: 0x5ee21072,
diff --git a/utils/uf2conv.py b/utils/uf2conv.py
index bb6c869..7c843d7 100644
--- a/utils/uf2conv.py
+++ b/utils/uf2conv.py
@@ -14,6 +14,7 @@ UF2_MAGIC_END    = 0x0AB16F30 # Ditto
 
 families = {
     'SAMD21': 0x68ed2b88,
+    'SAML21': 0x1851780a,
     'SAMD51': 0x55114460,
     'NRF52': 0x1b57745f,
     'STM32F1': 0x5ee21072,