diff --git a/src/librustdoc/html/highlight/tests.rs b/src/librustdoc/html/highlight/tests.rs
index 305cf61091dc6..a0da2c963d167 100644
--- a/src/librustdoc/html/highlight/tests.rs
+++ b/src/librustdoc/html/highlight/tests.rs
@@ -2,6 +2,7 @@ use super::write_code;
 use crate::html::format::Buffer;
 use expect_test::expect_file;
 use rustc_span::edition::Edition;
+use rustc_span::with_default_session_globals;
 
 const STYLE: &str = r#"
 <style>
@@ -17,21 +18,25 @@ const STYLE: &str = r#"
 
 #[test]
 fn test_html_highlighting() {
-    let src = include_str!("fixtures/sample.rs");
-    let html = {
-        let mut out = Buffer::new();
-        write_code(&mut out, src, Edition::Edition2018);
-        format!("{}<pre><code>{}</code></pre>\n", STYLE, out.into_inner())
-    };
-    expect_file!["fixtures/sample.html"].assert_eq(&html);
+    with_default_session_globals(|| {
+        let src = include_str!("fixtures/sample.rs");
+        let html = {
+            let mut out = Buffer::new();
+            write_code(&mut out, src, Edition::Edition2018);
+            format!("{}<pre><code>{}</code></pre>\n", STYLE, out.into_inner())
+        };
+        expect_file!["fixtures/sample.html"].assert_eq(&html);
+    });
 }
 
 #[test]
 fn test_dos_backline() {
-    let src = "pub fn foo() {\r\n\
+    with_default_session_globals(|| {
+        let src = "pub fn foo() {\r\n\
     println!(\"foo\");\r\n\
 }\r\n";
-    let mut html = Buffer::new();
-    write_code(&mut html, src, Edition::Edition2018);
-    expect_file!["fixtures/dos_line.html"].assert_eq(&html.into_inner());
+        let mut html = Buffer::new();
+        write_code(&mut html, src, Edition::Edition2018);
+        expect_file!["fixtures/dos_line.html"].assert_eq(&html.into_inner());
+    });
 }