diff --git a/src/tools/run-make-support/src/lib.rs b/src/tools/run-make-support/src/lib.rs
index 446afa1f82ec3..03b1a7efaaddf 100644
--- a/src/tools/run-make-support/src/lib.rs
+++ b/src/tools/run-make-support/src/lib.rs
@@ -64,6 +64,12 @@ pub fn python_command() -> Command {
     Command::new(python_path)
 }
 
+pub fn htmldocck() -> Command {
+    let mut python = python_command();
+    python.arg(source_path().join("/src/etc/htmldocck.py"));
+    python
+}
+
 pub fn source_path() -> PathBuf {
     std::env::var("S").expect("S variable does not exist").into()
 }
diff --git a/src/tools/tidy/src/allowed_run_make_makefiles.txt b/src/tools/tidy/src/allowed_run_make_makefiles.txt
index b84c147395dda..dd90c4e60d689 100644
--- a/src/tools/tidy/src/allowed_run_make_makefiles.txt
+++ b/src/tools/tidy/src/allowed_run_make_makefiles.txt
@@ -243,7 +243,6 @@ run-make/rustdoc-scrape-examples-multiple/Makefile
 run-make/rustdoc-scrape-examples-remap/Makefile
 run-make/rustdoc-scrape-examples-test/Makefile
 run-make/rustdoc-scrape-examples-whitespace/Makefile
-run-make/rustdoc-themes/Makefile
 run-make/rustdoc-verify-output-files/Makefile
 run-make/rustdoc-with-out-dir-option/Makefile
 run-make/rustdoc-with-output-option/Makefile
diff --git a/tests/run-make/rustdoc-scrape-examples-ordering/rmake.rs b/tests/run-make/rustdoc-scrape-examples-ordering/rmake.rs
index edcf3406d47f8..08ca9ce5de817 100644
--- a/tests/run-make/rustdoc-scrape-examples-ordering/rmake.rs
+++ b/tests/run-make/rustdoc-scrape-examples-ordering/rmake.rs
@@ -1,4 +1,4 @@
-use run_make_support::{python_command, rustc, rustdoc, source_path, tmp_dir};
+use run_make_support::{htmldocck, rustc, rustdoc, source_path, tmp_dir};
 use std::fs::read_dir;
 use std::path::Path;
 
@@ -45,11 +45,5 @@ fn main() {
     }
     rustdoc.run();
 
-    python_command()
-        .arg(source_path().join("/src/etc/htmldocck.py"))
-        .arg(out_dir)
-        .arg("src/lib.rs")
-        .status()
-        .unwrap()
-        .success();
+    htmldocck().arg(out_dir).arg("src/lib.rs").status().unwrap().success();
 }
diff --git a/tests/run-make/rustdoc-themes/Makefile b/tests/run-make/rustdoc-themes/Makefile
deleted file mode 100644
index a4980eb0b3e4d..0000000000000
--- a/tests/run-make/rustdoc-themes/Makefile
+++ /dev/null
@@ -1,11 +0,0 @@
-include ../tools.mk
-
-# Test that rustdoc will properly load in a theme file and display it in the theme selector.
-
-OUTPUT_DIR := "$(TMPDIR)/rustdoc-themes"
-
-all:
-	awk '/Begin theme: light/ {in_theme=1;next} /End theme:/ {in_theme=0} { if (in_theme) print }' \
-		< '$(S)/src/librustdoc/html/static/css/noscript.css' > '$(TMPDIR)/test.css'
-	$(RUSTDOC) -o $(OUTPUT_DIR) foo.rs --theme $(TMPDIR)/test.css
-	$(HTMLDOCCK) $(OUTPUT_DIR) foo.rs
diff --git a/tests/run-make/rustdoc-themes/rmake.rs b/tests/run-make/rustdoc-themes/rmake.rs
new file mode 100644
index 0000000000000..1d7dfe6bb2a09
--- /dev/null
+++ b/tests/run-make/rustdoc-themes/rmake.rs
@@ -0,0 +1,31 @@
+// Test that rustdoc will properly load in a theme file and display it in the theme selector.
+
+use run_make_support::{htmldocck, rustdoc, source_path, tmp_dir};
+
+fn main() {
+    let out_dir = tmp_dir().join("rustdoc-themes");
+    let test_css = out_dir.join("test.css");
+
+    let no_script =
+        std::fs::read_to_string(source_path().join("src/librustdoc/html/static/css/noscript.css"))
+            .unwrap();
+
+    let mut test_content = String::new();
+    let mut found_begin_light = false;
+    for line in no_script.split('\n') {
+        if line == "/* Begin theme: light */" {
+            found_begin_light = true;
+        } else if line == "/* End theme: light */" {
+            break;
+        } else if found_begin_light {
+            test_content.push_str(line);
+            test_content.push('\n');
+        }
+    }
+    assert!(!test_content.is_empty());
+    std::fs::create_dir_all(&out_dir).unwrap();
+    std::fs::write(&test_css, test_content).unwrap();
+
+    rustdoc().output(&out_dir).input("foo.rs").arg("--theme").arg(&test_css).run();
+    htmldocck().arg(out_dir).arg("foo.rs").status().unwrap().success();
+}