diff --git a/radio/src/CMakeLists.txt b/radio/src/CMakeLists.txt
index a0dc25011..0ec0575c6 100644
--- a/radio/src/CMakeLists.txt
+++ b/radio/src/CMakeLists.txt
@@ -480,6 +480,9 @@ if(NATIVE_BUILD)
   return()
 endif()
 
+# Silence CMake 2.8+ warning about unused variable (ie. if specified when not relevant)
+set(ignore_USE_UNSUPPORTED_TOOLCHAIN "${USE_UNSUPPORTED_TOOLCHAIN}")
+
 if(NOT USE_UNSUPPORTED_TOOLCHAIN AND NOT CMAKE_CXX_COMPILER_VERSION VERSION_EQUAL "14.2.1")
   message("CPP Compiler: ${CMAKE_CXX_COMPILER}, version ${CMAKE_CXX_COMPILER_VERSION}")
   message(FATAL_ERROR "Only Arm GNU Toolchain version 14.2.rel1 is supported!!")