diff --git a/.github/workflows/bazel-gcc-c++23-no-stl.yml b/.github/workflows/bazel-gcc-c++23-no-stl.yml
index 648e0bcb..1521793d 100644
--- a/.github/workflows/bazel-gcc-c++23-no-stl.yml
+++ b/.github/workflows/bazel-gcc-c++23-no-stl.yml
@@ -44,7 +44,7 @@ jobs:
     - uses: actions/checkout@v6.0.3
 
     - name: Build
-      run: bazel build //test:etl_tests --cxxopt=-std=c++23 --copt=-DETL_NO_STL
+      run: bazel build //test:etl_tests --cxxopt=-std=c++23 --copt=-DETL_NO_STL --//:etl_profile=//:no_profile
 
     - name: Run tests
-      run: bazel test //test:etl_tests --cxxopt=-std=c++23 --copt=-DETL_NO_STL --test_output=all
+      run: bazel test //test:etl_tests --cxxopt=-std=c++23 --copt=-DETL_NO_STL  --//:etl_profile=//:no_profile --test_output=all
diff --git a/BUILD.bazel b/BUILD.bazel
index 59ea5184..83d337ac 100644
--- a/BUILD.bazel
+++ b/BUILD.bazel
@@ -20,14 +20,23 @@ package(default_visibility = ["//visibility:public"])
 #         strip_include_prefix = ".",
 #     )
 #
-# The default is empty, so ETL's built-in defaults are used unless overridden.
+# The default of this label_flag is incompatible. This makes sure that the consumer
+# explicitly sets a profile, even if it is the `no_profile` defined below.
+
 label_flag(
     name = "etl_profile",
-    build_setting_default = ":no_profile",
+    build_setting_default = ":incompatible_profile",
 )
 
 cc_library(name = "no_profile")
 
+cc_library(
+    name = "incompatible_profile",
+    target_compatible_with = [
+        "@platforms//:incompatible",
+    ],
+)
+
 cc_library(
     name = "etl",
     hdrs = glob(["include/**/*.h"]),