diff --git a/environments/arm-linux/default_toolchain_file.cmake b/environments/arm-linux/default_toolchain_file.cmake
index bc04fdd..5ad7801 100644
--- a/environments/arm-linux/default_toolchain_file.cmake
+++ b/environments/arm-linux/default_toolchain_file.cmake
@@ -1,10 +1,12 @@
 #-------------------------------------------------------------------------------
-# Copyright (c) 2020, Arm Limited and Contributors. All rights reserved.
+# Copyright (c) 2020-2021, Arm Limited and Contributors. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
 #-------------------------------------------------------------------------------
-set(ENV{CROSS_COMPILE} "aarch64-linux-gnu-;aarch64-none-linux-gnu-")
+if(NOT CROSS_COMPILE AND NOT DEFINED ENV{CROSS_COMPILE})
+        set(CROSS_COMPILE "aarch64-elf-;aarch64-none-elf-;aarch64-linux-gnu-" CACHE STRING "List of GCC prefix triplets to use.")
+endif()
 
 set(CMAKE_CROSSCOMPILING True)
 set(CMAKE_SYSTEM_NAME Linux)
diff --git a/environments/opteesp/default_toolchain_file.cmake b/environments/opteesp/default_toolchain_file.cmake
index 76c78d7..76109ca 100644
--- a/environments/opteesp/default_toolchain_file.cmake
+++ b/environments/opteesp/default_toolchain_file.cmake
@@ -1,12 +1,12 @@
 #-------------------------------------------------------------------------------
-# Copyright (c) 2020, Arm Limited and Contributors. All rights reserved.
+# Copyright (c) 2020-2021, Arm Limited and Contributors. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
 #-------------------------------------------------------------------------------
 
 #GNUARM v8 and v9 compilers use a different triplet.
-if(NOT DEFINED ENV{CROSS_COMPILE})
+if(NOT CROSS_COMPILE AND NOT DEFINED ENV{CROSS_COMPILE})
 	set(CROSS_COMPILE "aarch64-elf-;aarch64-none-elf-;aarch64-linux-gnu-" CACHE STRING "List of GCC prefix triplets to use.")
 endif()