diff --git a/VARIANT_COMPLIANCE_CHANGELOG b/VARIANT_COMPLIANCE_CHANGELOG
index 0b13a212d19b21b52418c018636d1105c96ec2da..bf1c2fe214b0d865debf2665cd386ccad904a848 100644
--- a/VARIANT_COMPLIANCE_CHANGELOG
+++ b/VARIANT_COMPLIANCE_CHANGELOG
@@ -1,4 +1,4 @@
-SAMD CORE 1.6.5
+SAMD CORE 1.6.6
 
 * digitalPinToInterrupt #define moved to Arduino.h, variant.h must no longer define it
 
diff --git a/cores/arduino/Arduino.h b/cores/arduino/Arduino.h
index 97a1342f339391325c89d2e196883dd7e9120903..3bafdb5fc4aac8a3059114fc53aaf8b2b990afe9 100644
--- a/cores/arduino/Arduino.h
+++ b/cores/arduino/Arduino.h
@@ -114,7 +114,7 @@ void loop( void ) ;
 
 #define bit(b) (1UL << (b))
 
-#if (ARDUINO_SAMD_VARIANT_COMPLIANCE >= 10605)
+#if (ARDUINO_SAMD_VARIANT_COMPLIANCE >= 10606)
 // Interrupts
 #define digitalPinToInterrupt(P)   ( P )
 #endif
diff --git a/cores/arduino/WInterrupts.c b/cores/arduino/WInterrupts.c
index 430195ca18932ce3d152ab48ff4da96175f5eed9..70d9acd017d9b456be47b0256af2f1b9ceec2ae5 100644
--- a/cores/arduino/WInterrupts.c
+++ b/cores/arduino/WInterrupts.c
@@ -57,7 +57,7 @@ void attachInterrupt(uint32_t pin, voidFuncPtr callback, uint32_t mode)
   uint32_t config;
   uint32_t pos;
 
-#if ARDUINO_SAMD_VARIANT_COMPLIANCE >= 10605
+#if ARDUINO_SAMD_VARIANT_COMPLIANCE >= 10606
   EExt_Interrupts in = g_APinDescription[pin].ulExtInt;
 #else
   EExt_Interrupts in = digitalPinToInterrupt(pin);
@@ -120,7 +120,7 @@ void attachInterrupt(uint32_t pin, voidFuncPtr callback, uint32_t mode)
  */
 void detachInterrupt(uint32_t pin)
 {
-#if (ARDUINO_SAMD_VARIANT_COMPLIANCE >= 10605)
+#if (ARDUINO_SAMD_VARIANT_COMPLIANCE >= 10606)
   EExt_Interrupts in = g_APinDescription[pin].ulExtInt;
 #else
   EExt_Interrupts in = digitalPinToInterrupt(pin);
diff --git a/variants/arduino_zero/variant.h b/variants/arduino_zero/variant.h
index 8bfe71c5b60dbcf1a392ae77b41f802d8a120af8..cb88edb289e4375d3ff8a65c8f2be0a04b96579e 100644
--- a/variants/arduino_zero/variant.h
+++ b/variants/arduino_zero/variant.h
@@ -19,8 +19,8 @@
 #ifndef _VARIANT_ARDUINO_ZERO_
 #define _VARIANT_ARDUINO_ZERO_
 
-// The definitions here needs a SAMD core >=1.6.5
-#define ARDUINO_SAMD_VARIANT_COMPLIANCE 10605
+// The definitions here needs a SAMD core >=1.6.6
+#define ARDUINO_SAMD_VARIANT_COMPLIANCE 10606
 
 /*----------------------------------------------------------------------------
  *        Definitions