diff --git a/conf/distro/include/tcmode-external-sourcery.inc b/conf/distro/include/tcmode-external-sourcery.inc
index 1494cd4..dd4ff39 100644
--- a/conf/distro/include/tcmode-external-sourcery.inc
+++ b/conf/distro/include/tcmode-external-sourcery.inc
@@ -48,6 +48,10 @@ ENABLE_BINARY_LOCALE_GENERATION = ""
 
 TOOLCHAIN_OPTIONS = " --sysroot=${STAGING_DIR_HOST}"
 
+CSL_IS_PRO := "${@'1' if os.path.exists('${EXTERNAL_TOOLCHAIN}/license') else '0'}"
+
+TUNE_CCARGS_append_x86 = "${@'-msgxx-glibc' if CSL_IS_PRO == '1' else ''}"
+
 # Unfortunately, the CSL ia32 toolchain has non-prefixed binaries in its
 # bindir (e.g. gcc, ld). To avoid this messing up our build, we avoid adding
 # this bindir to our PATH, and instead add symlinks to the prefixed binaries
@@ -76,10 +80,6 @@ python toolchain_metadata_setup () {
     if os.path.exists(bb.data.expand('${EXTERNAL_TOOLCHAIN}/bin/gcc', l)):
         d.setVar('TOOLCHAIN_PATH_ADD', '')
 
-    if os.path.exists(bb.data.expand('${EXTERNAL_TOOLCHAIN}/license', l)):
-        # Assuming use of a CodeBench Pro toolchain
-        d.setVar('TUNE_CCARGS_append_x86', " -msgxx-glibc")
-
     # The external toolchain may not have been built with the yocto preferred
     # gnu hash setting, so ensure that the corresponding sanity check is a
     # warning, not an error.