diff --git a/swift/internal/swift_autoconfiguration.bzl b/swift/internal/swift_autoconfiguration.bzl
index 0591f9801..d63912a93 100644
--- a/swift/internal/swift_autoconfiguration.bzl
+++ b/swift/internal/swift_autoconfiguration.bzl
@@ -237,12 +237,6 @@ def _create_linux_toolchain(repository_ctx):
     Args:
       repository_ctx: The repository rule context.
     """
-    cc = repository_ctx.os.environ.get("CC") or ""
-    if "clang" not in cc:
-        fail("ERROR: rules_swift uses Bazel's CROSSTOOL to link, but Swift " +
-             "requires that the driver used is clang. Please set `CC=clang` " +
-             "in your environment before invoking Bazel.")
-
     path_to_swiftc = repository_ctx.which("swiftc")
     if not path_to_swiftc:
         fail("No 'swiftc' executable found in $PATH")
diff --git a/swift/internal/swift_toolchain.bzl b/swift/internal/swift_toolchain.bzl
index 05624ccdf..a9801aa57 100644
--- a/swift/internal/swift_toolchain.bzl
+++ b/swift/internal/swift_toolchain.bzl
@@ -266,6 +266,11 @@ def _swift_toolchain_impl(ctx):
     toolchain_root = ctx.attr.root
     cc_toolchain = find_cpp_toolchain(ctx)
 
+    if cc_toolchain.compiler != "clang":
+        fail("Swift requires the configured CC toolchain to be LLVM (clang). " +
+             "Either use the locally installed LLVM by setting `CC=clang` in your environment " +
+             "before invoking Bazel, or configure a Bazel LLVM CC toolchain.")
+
     if ctx.attr.os == "windows":
         swift_linkopts_cc_info = _swift_windows_linkopts_cc_info(
             ctx.attr.arch,