diff --git a/devlib/platform/arm.py b/devlib/platform/arm.py
index 2f60c56..238acf0 100644
--- a/devlib/platform/arm.py
+++ b/devlib/platform/arm.py
@@ -177,7 +177,6 @@ class Juno(VersatileExpressPlatform):
                  baudrate=115200,
                  bootloader='u-boot',
                  hard_reset_method='dtr',
-                 big_core='a57',
                  **kwargs
                  ):
         super(Juno, self).__init__('juno',
@@ -185,7 +184,6 @@ class Juno(VersatileExpressPlatform):
                                    baudrate=baudrate,
                                    bootloader=bootloader,
                                    hard_reset_method=hard_reset_method,
-                                   big_core='a57',
                                    **kwargs)
 
 
@@ -196,7 +194,6 @@ class TC2(VersatileExpressPlatform):
                  baudrate=38400,
                  bootloader='bootmon',
                  hard_reset_method='reboottxt',
-                 big_core='a15',
                  **kwargs
                  ):
         super(TC2, self).__init__('tc2',
@@ -204,7 +201,6 @@ class TC2(VersatileExpressPlatform):
                                   baudrate=baudrate,
                                   bootloader=bootloader,
                                   hard_reset_method=hard_reset_method,
-                                  big_core='a15',
                                   **kwargs)