diff --git a/targets/targets.json b/targets/targets.json
index 00131b1a80..0652c7f330 100644
--- a/targets/targets.json
+++ b/targets/targets.json
@@ -6650,7 +6650,7 @@
             "TC_ASYNC=true"
         ],
         "extra_labels": ["Atmel", "SAM_CortexM0P", "SAMR21"],
-        "supported_toolchains": ["GCC_ARM", "ARM", "uARM"],
+        "supported_toolchains": ["GCC_ARM", "ARMC5", "uARM"],
         "device_has": [
             "ANALOGIN",
             "I2C",
@@ -6683,7 +6683,7 @@
             "TC_ASYNC=true"
         ],
         "extra_labels": ["Atmel", "SAM_CortexM0P", "SAMD21"],
-        "supported_toolchains": ["GCC_ARM", "ARM", "uARM"],
+        "supported_toolchains": ["GCC_ARM", "ARMC5", "uARM"],
         "device_has": [
             "ANALOGIN",
             "ANALOGOUT",
@@ -6717,7 +6717,7 @@
             "TC_ASYNC=true"
         ],
         "extra_labels": ["Atmel", "SAM_CortexM0P", "SAMD21"],
-        "supported_toolchains": ["GCC_ARM", "ARM", "uARM"],
+        "supported_toolchains": ["GCC_ARM", "ARMC5", "uARM"],
         "device_has": [
             "ANALOGIN",
             "ANALOGOUT",
@@ -6751,7 +6751,7 @@
             "TC_ASYNC=true"
         ],
         "extra_labels": ["Atmel", "SAM_CortexM0P", "SAML21"],
-        "supported_toolchains": ["GCC_ARM", "ARM", "uARM"],
+        "supported_toolchains": ["GCC_ARM", "ARMC5", "uARM"],
         "device_has": [
             "ANALOGIN",
             "ANALOGOUT",
diff --git a/tools/build.py b/tools/build.py
index 51087c3b1d..7fd477a441 100644
--- a/tools/build.py
+++ b/tools/build.py
@@ -182,9 +182,8 @@ def main():
             except NoValidToolchainException as e:
                 print_end_warnings(e.end_warnings)
                 args_error(parser, str(e))
-
             tt_id = "%s::%s" % (internal_tc_name, target_name)
-            if not target_supports_toolchain(target, toolchain):
+            if not target_supports_toolchain(target, toolchain_name):
                 # Log this later
                 print("%s skipped: toolchain not supported" % tt_id)
                 skipped.append(tt_id)
@@ -196,7 +195,6 @@ def main():
                     if target.is_PSA_secure_target and \
                             not is_relative_to_root(options.source_dir):
                         options.source_dir = ROOT
-
                     if options.source_dir:
                         lib_build_res = build_library(
                             options.source_dir, options.build_dir, target, toolchain_name,
diff --git a/tools/build_api.py b/tools/build_api.py
index 3c301e7ce3..d65fca5d85 100755
--- a/tools/build_api.py
+++ b/tools/build_api.py
@@ -988,7 +988,6 @@ def build_mbed_libs(target, toolchain_name, clean=False, macros=None,
     #then set the default_toolchain to uARM to link AC6 microlib.
     if(selected_toolchain_name == "ARMC6" and toolchain_name == "uARM"):
         target.default_toolchain = "uARM"
-    toolchain_name = selected_toolchain_name
 
     if report is not None:
         start = time()
@@ -1003,7 +1002,7 @@ def build_mbed_libs(target, toolchain_name, clean=False, macros=None,
             prep_properties(
                 properties, target.name, toolchain_name, vendor_label)
 
-    if toolchain_name not in target.supported_toolchains:
+    if not target_supports_toolchain(target, toolchain_name):
         supported_toolchains_text = ", ".join(target.supported_toolchains)
         notify.info('The target {} does not support the toolchain {}'.format(
             target.name,
@@ -1023,14 +1022,16 @@ def build_mbed_libs(target, toolchain_name, clean=False, macros=None,
 
     try:
         # Source and Build Paths
+
         build_toolchain = join(
-            MBED_LIBRARIES, mbed2_obj_path(target.name, toolchain_name))
+            MBED_LIBRARIES, mbed2_obj_path(target.name, selected_toolchain_name)
+        )
         mkdir(build_toolchain)
 
         tmp_path = join(
             MBED_LIBRARIES,
             '.temp',
-            mbed2_obj_path(target.name, toolchain_name)
+            mbed2_obj_path(target.name, selected_toolchain_name)
         )
         mkdir(tmp_path)