diff --git a/builder/frameworks/arduino/arduino-samd.py b/builder/frameworks/arduino/arduino-samd.py
index 53db7e5..9e11380 100644
--- a/builder/frameworks/arduino/arduino-samd.py
+++ b/builder/frameworks/arduino/arduino-samd.py
@@ -181,9 +181,15 @@
     CLEARCORE_BASE_DIR = platform.get_package_dir("framework-arduino-samd-clearcore")
     CLEARCORE_LIB_DIR = os.path.join(CLEARCORE_BASE_DIR, "Teknic")
 
-    env.Append(
+
+    env.Prepend(
         CPPPATH=[
             os.path.join(CLEARCORE_BASE_DIR, "variants", "clearcore", "ThirdParty", "SAME53", "CMSIS", "Device", "Include"),
+        ]
+    )
+
+    env.Append(
+        CPPPATH=[
             os.path.join(CLEARCORE_BASE_DIR, "cores", "arduino", "api"),
             os.path.join(CLEARCORE_BASE_DIR, "cores", "arduino"),
             os.path.join(CLEARCORE_BASE_DIR, "variants", "clearcore"),
@@ -199,8 +205,7 @@
 
         LIBS=[
             "ClearCore",
-            "LwIP",
-            "arm_cortexM4lf_math"
+            "LwIP"
         ]
     )
 
diff --git a/platform.py b/platform.py
index ad4347d..f68f279 100644
--- a/platform.py
+++ b/platform.py
@@ -76,7 +76,7 @@ def configure_default_packages(self, variables, targets):
             if build_core in ("adafruit", "seeed"):
                 self.packages["framework-cmsis"]["version"] = "~2.50400.0"
             if build_core == "clearcore":
-                self.packages["framework-cmsis"]["version"] = "~2.50700"
+                self.packages["framework-cmsis"]["version"] = "~1.40500.0"
 
         if (
             board.get("build.core", "") in ("adafruit", "seeed", "sparkfun")