diff --git a/BUILD.gn b/BUILD.gn
index f0319a303..5514010b1 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -17,9 +17,15 @@ import("$dir_pw_unit_test/test.gni")
 # By default, Pigweed will build this target when invoking ninja.
 group("default") {
   deps = [
-    ":pw_module_tests_run",
     "$dir_pigweed/docs",
   ]
+  if (pw_automatic_test_runner == "") {
+    # Without a test runner defined, build the tests but don't run them.
+    deps += [ ":pw_module_tests" ]
+  } else {
+    # With a test runner, depend on the run targets so they run with the build.
+    deps += [ ":pw_module_tests_run" ]
+  }
 }
 
 group("pw_facades") {