diff --git a/scripts/west_commands/build_helpers.py b/scripts/west_commands/build_helpers.py
index 7f3b7021de5..3303bc67cbb 100644
--- a/scripts/west_commands/build_helpers.py
+++ b/scripts/west_commands/build_helpers.py
@@ -21,22 +21,25 @@ DEFAULT_CMAKE_GENERATOR = 'Ninja'
 '''Name of the default CMake generator.'''
 
 BUILD_DIR_DESCRIPTION = '''\
-Build directory. If missing and run in a Zephyr build directory, it is
-used; otherwise, it's "{}".'''.format(
-    DEFAULT_BUILD_DIR)
+Build directory. If not given, {}/ is used; otherwise if the current directory
+is a Zephyr build directory, it is used.'''.format(DEFAULT_BUILD_DIR)
 
 
 def find_build_dir(dir):
     '''Heuristic for finding a build directory.
 
-    If the given argument is truthy, it is returned. Otherwise, if
+    If the given argument is truthy, it is returned. Otherwise if the
+    DEFAULT_BUILD_DIR is a build directory, it is returned. Next, if
     the current working directory is a build directory, it is
-    returned. Otherwise, DEFAULT_BUILD_DIR is returned.'''
+    returned. Finally, DEFAULT_BUILD_DIR is returned.'''
     if dir:
         build_dir = dir
     else:
         cwd = os.getcwd()
-        if is_zephyr_build(cwd):
+        default = os.path.join(cwd, DEFAULT_BUILD_DIR)
+        if is_zephyr_build(default):
+            build_dir = default
+        elif is_zephyr_build(cwd):
             build_dir = cwd
         else:
             build_dir = DEFAULT_BUILD_DIR
diff --git a/scripts/west_commands/run_common.py b/scripts/west_commands/run_common.py
index 5c4f8579f13..1b36b66cb29 100644
--- a/scripts/west_commands/run_common.py
+++ b/scripts/west_commands/run_common.py
@@ -13,7 +13,7 @@ import textwrap
 from west import cmake
 from west import log
 from west import util
-from west.build import DEFAULT_BUILD_DIR, is_zephyr_build
+from build_helpers import find_build_dir, is_zephyr_build
 from west.commands import CommandContextError
 
 from runners import get_runner_cls, ZephyrBinaryRunner
@@ -128,16 +128,14 @@ def _build_dir(args, die_if_none=True):
     if args.build_dir:
         return args.build_dir
 
-    cwd = getcwd()
-    default = path.join(cwd, DEFAULT_BUILD_DIR)
-    if is_zephyr_build(default):
-        return default
-    elif is_zephyr_build(cwd):
-        return cwd
+    dir = find_build_dir(None)
+
+    if is_zephyr_build(dir):
+        return dir
     elif die_if_none:
         log.die('--build-dir was not given, and neither {} '
                 'nor {} are zephyr build directories.'.
-                format(default, cwd))
+                format(getcwd(), dir))
     else:
         return None