diff --git a/CHANGELOG b/CHANGELOG
index be552878..f9bb22ad 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -4,6 +4,7 @@ SAMD CORE 1.6.12 2017.02.02
 * Fixed pinMode(pin, OUTPUT) not working after analogRead(pin)
 * Reenabled support for Tian
 * Fixed signature for Adafruit Circuit Playground Express board
+* Added CMSIS headers for SAML21 chip series. Thanks @aethaniel
 
 SAMD CORE 1.6.11 2016.12.23
 
diff --git a/extras/package_index.json.Hourly.template b/extras/package_index.json.Hourly.template
index fdc1918a..a784602e 100644
--- a/extras/package_index.json.Hourly.template
+++ b/extras/package_index.json.Hourly.template
@@ -47,7 +47,7 @@
             {
               "packager": "arduino",
               "name": "CMSIS-Atmel",
-              "version": "1.0.0"
+              "version": "1.1.0"
             }
           ]
         }
diff --git a/extras/package_index.json.PR.template b/extras/package_index.json.PR.template
index ff4b26f6..7f576724 100644
--- a/extras/package_index.json.PR.template
+++ b/extras/package_index.json.PR.template
@@ -47,7 +47,7 @@
             {
               "packager": "arduino",
               "name": "CMSIS-Atmel",
-              "version": "1.0.0"
+              "version": "1.1.0"
             }
           ]
         }
diff --git a/platform.txt b/platform.txt
index 54165984..a5ad1df6 100644
--- a/platform.txt
+++ b/platform.txt
@@ -64,7 +64,7 @@ compiler.S.extra_flags=
 compiler.ar.extra_flags=
 compiler.elf2hex.extra_flags=
 
-compiler.arm.cmsis.c.flags="-I{runtime.tools.CMSIS-4.5.0.path}/CMSIS/Include/" "-I{runtime.tools.CMSIS-Atmel-1.0.0.path}/CMSIS/Device/ATMEL/"
+compiler.arm.cmsis.c.flags="-I{runtime.tools.CMSIS-4.5.0.path}/CMSIS/Include/" "-I{runtime.tools.CMSIS-Atmel-1.1.0.path}/CMSIS/Device/ATMEL/"
 compiler.arm.cmsis.ldflags="-L{runtime.tools.CMSIS-4.5.0.path}/CMSIS/Lib/GCC/" -larm_cortexM0l_math
 
 # USB Flags