diff --git a/Android/android.py b/Android/android.py
index adcc7c708d95f7..f9f6de73803ff1 100755
--- a/Android/android.py
+++ b/Android/android.py
@@ -398,9 +398,15 @@ def setup_testbed():
 def build_testbed(context):
     setup_sdk()
     setup_testbed()
+
+    # Ensure that CROSS_BUILD_DIR is in the Gradle environment, regardless
+    # of whether it was set by environment variable or `--cross-build-dir`.
+    env = os.environ.copy()
+    env["CROSS_BUILD_DIR"] = CROSS_BUILD_DIR
     run(
         [gradlew, "--console", "plain", "packageDebug", "packageDebugAndroidTest"],
         cwd=TESTBED_DIR,
+        env=env,
     )
 
 
@@ -645,6 +651,10 @@ async def gradle_task(context):
         task_prefix = "connected"
         env["ANDROID_SERIAL"] = context.connected
 
+    # Ensure that CROSS_BUILD_DIR is in the Gradle environment, regardless
+    # of whether it was set by environment variable or `--cross-build-dir`.
+    env["CROSS_BUILD_DIR"] = CROSS_BUILD_DIR
+
     if context.ci_mode:
         context.args[0:0] = [
             # See _add_ci_python_opts in libregrtest/main.py.
@@ -896,7 +906,7 @@ def add_parser(*args, **kwargs):
         help="Delete build directories for the selected target"
     )
 
-    add_parser("build-testbed", help="Build the testbed app")
+    build_testbed = add_parser("build-testbed", help="Build the testbed app")
     test = add_parser("test", help="Run the testbed app")
     package = add_parser("package", help="Make a release package")
     ci = add_parser("ci", help="Run build, package and test")
@@ -912,6 +922,7 @@ def add_parser(*args, **kwargs):
         make_host,
         build,
         package,
+        build_testbed,
         test,
         ci,
     ]:
diff --git a/Android/testbed/app/build.gradle.kts b/Android/testbed/app/build.gradle.kts
index b58edc04a929d9..2a0544907cf508 100644
--- a/Android/testbed/app/build.gradle.kts
+++ b/Android/testbed/app/build.gradle.kts
@@ -8,7 +8,10 @@ plugins {
 
 val ANDROID_DIR = file("../..")
 val PYTHON_DIR = ANDROID_DIR.parentFile!!
-val PYTHON_CROSS_DIR = file("$PYTHON_DIR/cross-build")
+val CROSS_BUILD_DIR = System.getenv("CROSS_BUILD_DIR") ?: "cross-build"
+val PYTHON_CROSS_DIR = file(
+    if ((File(CROSS_BUILD_DIR)).isAbsolute) CROSS_BUILD_DIR else "$PYTHON_DIR/$CROSS_BUILD_DIR"
+)
 val inSourceTree = (
     ANDROID_DIR.name == "Android" && file("$PYTHON_DIR/pyconfig.h.in").exists()
 )