diff --git a/cibuildwheel/linux.py b/cibuildwheel/linux.py
index 5cc19bf55..f5d8710e1 100644
--- a/cibuildwheel/linux.py
+++ b/cibuildwheel/linux.py
@@ -241,7 +241,7 @@ def build_in_container(
 
             verbosity_flags = get_build_verbosity_extra_flags(build_options.build_verbosity)
             extra_flags = split_config_settings(
-                build_options.config_settings, plural=build_options.build_frontend == "pip"
+                build_options.config_settings, build_options.build_frontend
             )
 
             if build_options.build_frontend == "pip":
diff --git a/cibuildwheel/macos.py b/cibuildwheel/macos.py
index 49068ab89..3bb1324db 100644
--- a/cibuildwheel/macos.py
+++ b/cibuildwheel/macos.py
@@ -375,7 +375,7 @@ def build(options: Options, tmp_path: Path) -> None:
 
                 verbosity_flags = get_build_verbosity_extra_flags(build_options.build_verbosity)
                 extra_flags = split_config_settings(
-                    build_options.config_settings, plural=build_options.build_frontend == "pip"
+                    build_options.config_settings, build_options.build_frontend
                 )
 
                 if build_options.build_frontend == "pip":
diff --git a/cibuildwheel/util.py b/cibuildwheel/util.py
index f217af081..72cff3260 100644
--- a/cibuildwheel/util.py
+++ b/cibuildwheel/util.py
@@ -208,9 +208,9 @@ def get_build_verbosity_extra_flags(level: int) -> list[str]:
         return []
 
 
-def split_config_settings(config_settings: str, *, plural: bool) -> list[str]:
+def split_config_settings(config_settings: str, frontend: Literal["pip", "build"]) -> list[str]:
     config_settings_list = shlex.split(config_settings)
-    s = "s" if plural else ""
+    s = "s" if frontend == "pip" else ""
     return [f"--config-setting{s}={setting}" for setting in config_settings_list]
 
 
diff --git a/cibuildwheel/windows.py b/cibuildwheel/windows.py
index 3eeee294d..cb83a324b 100644
--- a/cibuildwheel/windows.py
+++ b/cibuildwheel/windows.py
@@ -412,7 +412,7 @@ def build(options: Options, tmp_path: Path) -> None:
 
                 verbosity_flags = get_build_verbosity_extra_flags(build_options.build_verbosity)
                 extra_flags = split_config_settings(
-                    build_options.config_settings, plural=build_options.build_frontend == "pip"
+                    build_options.config_settings, build_options.build_frontend
                 )
 
                 if build_options.build_frontend == "pip":
diff --git a/unit_test/main_tests/main_options_test.py b/unit_test/main_tests/main_options_test.py
index ec9b0725d..6cda8967b 100644
--- a/unit_test/main_tests/main_options_test.py
+++ b/unit_test/main_tests/main_options_test.py
@@ -283,13 +283,13 @@ def test_config_settings(platform_specific, platform, intercepted_build_args, mo
 
     assert build_options.config_settings == config_settings
 
-    assert split_config_settings(config_settings, plural=False) == [
+    assert split_config_settings(config_settings, "build") == [
         "--config-setting=setting=value",
         "--config-setting=setting=value2",
         "--config-setting=other=something else",
     ]
 
-    assert split_config_settings(config_settings, plural=True) == [
+    assert split_config_settings(config_settings, "pip") == [
         "--config-settings=setting=value",
         "--config-settings=setting=value2",
         "--config-settings=other=something else",