diff --git a/src/bootstrap/mk/Makefile.in b/src/bootstrap/mk/Makefile.in
index 1e0f7e9acf4..9a08a7be0f5 100644
--- a/src/bootstrap/mk/Makefile.in
+++ b/src/bootstrap/mk/Makefile.in
@@ -80,7 +80,7 @@ TESTS_IN_MINGW_2 := \
 	src/test/ui
 
 ci-mingw-subset-1:
-	$(Q)$(CFG_SRC_DIR)/x.sh test --stage 2 $(TESTS_IN_MINGW_2:%=--exclude %)
+	$(Q)$(CFG_SRC_DIR)/x test --stage 2 $(TESTS_IN_MINGW_2:%=--exclude %)
 ci-mingw-subset-2:
 	$(Q)$(BOOTSTRAP) test --stage 2 $(TESTS_IN_MINGW_2)
 
diff --git a/src/ci/docker/host-x86_64/x86_64-gnu-llvm-12/Dockerfile b/src/ci/docker/host-x86_64/x86_64-gnu-llvm-12/Dockerfile
index 8de9045c3ba..14d0ffd7500 100644
--- a/src/ci/docker/host-x86_64/x86_64-gnu-llvm-12/Dockerfile
+++ b/src/ci/docker/host-x86_64/x86_64-gnu-llvm-12/Dockerfile
@@ -44,7 +44,7 @@ ENV RUST_CONFIGURE_ARGS \
       --enable-llvm-link-shared \
       --set rust.thin-lto-import-instr-limit=10
 
-# NOTE: intentionally uses all of `x.py`, `x.sh`, and `x.ps1` to make sure they all work on Linux.
+# NOTE: intentionally uses all of `x.py`, `x`, and `x.ps1` to make sure they all work on Linux.
 ENV SCRIPT ../x.py --stage 2 test --exclude src/tools/tidy && \
            # Run the `mir-opt` tests again but this time for a 32-bit target.
            # This enforces that tests using `// EMIT_MIR_FOR_EACH_BIT_WIDTH` have
@@ -52,7 +52,7 @@ ENV SCRIPT ../x.py --stage 2 test --exclude src/tools/tidy && \
            # the PR is approved and tested for merging.
            # It will also detect tests lacking `// EMIT_MIR_FOR_EACH_BIT_WIDTH`,
            # despite having different output on 32-bit vs 64-bit targets.
-           ../x.sh --stage 2 test src/test/mir-opt \
+           ../x --stage 2 test src/test/mir-opt \
                              --host='' --target=i686-unknown-linux-gnu && \
            # Run the UI test suite again, but in `--pass=check` mode
            #
diff --git a/src/tools/tidy/src/bins.rs b/src/tools/tidy/src/bins.rs
index 025b8ab9f0a..30903f56d93 100644
--- a/src/tools/tidy/src/bins.rs
+++ b/src/tools/tidy/src/bins.rs
@@ -98,7 +98,7 @@ mod os_impl {
     pub fn check(path: &Path, bad: &mut bool) {
         use std::ffi::OsStr;
 
-        const ALLOWED: &[&str] = &["configure"];
+        const ALLOWED: &[&str] = &["configure", "x"];
 
         crate::walk_no_read(
             path,
diff --git a/x.sh b/x
similarity index 100%
rename from x.sh
rename to x
diff --git a/x.ps1 b/x.ps1
index 1225443735f..86cea606591 100755
--- a/x.ps1
+++ b/x.ps1
@@ -1,6 +1,6 @@
 #!/usr/bin/env pwsh
 
-# See x.sh for why these scripts exist.
+# See ./x for why these scripts exist.
 
 $xpy = Join-Path $PSScriptRoot x.py
 # Start-Process for some reason splits arguments on spaces. (Isn't powershell supposed to be simpler than bash?)
diff --git a/x.py b/x.py
index 6c68907c581..6df4033d55d 100755
--- a/x.py
+++ b/x.py
@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 # Some systems don't have `python3` in their PATH. This isn't supported by x.py directly;
-# they should use `x.sh` or `x.ps1` instead.
+# they should use `x` or `x.ps1` instead.
 
 # This file is only a "symlink" to bootstrap.py, all logic should go there.