diff --git a/scripts/abi_check.py b/scripts/abi_check.py
index c228843..ac1d60f 100755
--- a/scripts/abi_check.py
+++ b/scripts/abi_check.py
@@ -113,6 +113,8 @@
 
 import xml.etree.ElementTree as ET
 
+from mbedtls_dev import build_tree
+
 
 class AbiChecker:
     """API and ABI checker."""
@@ -150,11 +152,6 @@
         self.git_command = "git"
         self.make_command = "make"
 
-    @staticmethod
-    def check_repo_path():
-        if not all(os.path.isdir(d) for d in ["include", "library", "tests"]):
-            raise Exception("Must be run from Mbed TLS root")
-
     def _setup_logger(self):
         self.log = logging.getLogger()
         if self.verbose:
@@ -540,7 +537,7 @@
     def check_for_abi_changes(self):
         """Generate a report of ABI differences
         between self.old_rev and self.new_rev."""
-        self.check_repo_path()
+        build_tree.check_repo_path()
         if self.check_api or self.check_abi:
             self.check_abi_tools_are_installed()
         self._get_abi_dump_for_ref(self.old_version)
diff --git a/scripts/mbedtls_dev/build_tree.py b/scripts/mbedtls_dev/build_tree.py
index 3920d0e..f52b785 100644
--- a/scripts/mbedtls_dev/build_tree.py
+++ b/scripts/mbedtls_dev/build_tree.py
@@ -25,6 +25,13 @@
     return all(os.path.isdir(os.path.join(path, subdir))
                for subdir in ['include', 'library', 'programs', 'tests'])
 
+def check_repo_path():
+    """
+    Check that the current working directory is the project root, and throw
+    an exception if not.
+    """
+    if not all(os.path.isdir(d) for d in ["include", "library", "tests"]):
+        raise Exception("This script must be run from Mbed TLS root")
 
 def chdir_to_root() -> None:
     """Detect the root of the Mbed TLS source tree and change to it.