diff --git a/src/librustc_privacy/diagnostics.rs b/src/librustc_privacy/diagnostics.rs
index 36ece929413db..66afe5835bf6f 100644
--- a/src/librustc_privacy/diagnostics.rs
+++ b/src/librustc_privacy/diagnostics.rs
@@ -16,7 +16,7 @@ E0445: r##"
 A private trait was used on a public type parameter bound. Erroneous code
 examples:
 
-```compile_fail
+```compile_fail,E0445
 #![deny(private_in_public)]
 
 trait Foo {
@@ -46,7 +46,7 @@ pub fn foo<T: Foo> (t: T) {} // ok!
 E0446: r##"
 A private type was used in a public type signature. Erroneous code example:
 
-```compile_fail
+```compile_fail,E0446
 #![deny(private_in_public)]
 
 mod Foo {
@@ -100,7 +100,7 @@ pub enum Foo {
 Since the enum is already public, adding `pub` on one its elements is
 unnecessary. Example:
 
-```compile_fail
+```compile_fail,
 enum Foo {
     pub Bar, // not ok!
 }
@@ -119,7 +119,7 @@ E0450: r##"
 A tuple constructor was invoked while some of its fields are private. Erroneous
 code example:
 
-```compile_fail
+```compile_fail,E0450
 mod Bar {
     pub struct Foo(isize);
 }
@@ -157,7 +157,7 @@ let f = bar::Foo::new(1);
 E0451: r##"
 A struct constructor with private fields was invoked. Erroneous code example:
 
-```compile_fail
+```compile_fail,E0451
 mod Bar {
     pub struct Foo {
         pub a: isize,
diff --git a/src/librustdoc/html/markdown.rs b/src/librustdoc/html/markdown.rs
index ed08f2f012332..139e1033175ea 100644
--- a/src/librustdoc/html/markdown.rs
+++ b/src/librustdoc/html/markdown.rs
@@ -605,18 +605,21 @@ mod tests {
         }
 
         // marker                | should_panic| no_run| ignore| rust | test_harness| compile_fail
-        t("",                      false,        false,  false,  true,  false,        false);
-        t("rust",                  false,        false,  false,  true,  false,        false);
-        t("sh",                    false,        false,  false,  false, false,        false);
-        t("ignore",                false,        false,  true,   true,  false,        false);
-        t("should_panic",          true,         false,  false,  true,  false,        false);
-        t("no_run",                false,        true,   false,  true,  false,        false);
-        t("test_harness",          false,        false,  false,  true,  true,         false);
-        t("compile_fail",          false,        true,   false,  true,  false,        true);
-        t("{.no_run .example}",    false,        true,   false,  true,  false,        false);
-        t("{.sh .should_panic}",   true,         false,  false,  true,  false,        false);
-        t("{.example .rust}",      false,        false,  false,  true,  false,        false);
-        t("{.test_harness .rust}", false,        false,  false,  true,  true,         false);
+        //                       | error_codes
+        t("",                      false,        false,  false,  true,  false, false, Vec::new());
+        t("rust",                  false,        false,  false,  true,  false, false, Vec::new());
+        t("sh",                    false,        false,  false,  false, false, false, Vec::new());
+        t("ignore",                false,        false,  true,   true,  false, false, Vec::new());
+        t("should_panic",          true,         false,  false,  true,  false, false, Vec::new());
+        t("no_run",                false,        true,   false,  true,  false, false, Vec::new());
+        t("test_harness",          false,        false,  false,  true,  true,  false, Vec::new());
+        t("compile_fail",          false,        true,   false,  true,  false, true,  Vec::new());
+        t("E0450",                 false,        false,  false,  true,  false, false,
+                                   vec!("E0450".to_owned()));
+        t("{.no_run .example}",    false,        true,   false,  true,  false, false, Vec::new());
+        t("{.sh .should_panic}",   true,         false,  false,  true,  false, false, Vec::new());
+        t("{.example .rust}",      false,        false,  false,  true,  false, false, Vec::new());
+        t("{.test_harness .rust}", false,        false,  false,  true,  true,  false, Vec::new());
     }
 
     #[test]
diff --git a/src/librustdoc/test.rs b/src/librustdoc/test.rs
index cb27da0a75978..c17af55ca10af 100644
--- a/src/librustdoc/test.rs
+++ b/src/librustdoc/test.rs
@@ -275,7 +275,7 @@ fn runtest(test: &str, cratename: &str, cfgs: Vec<String>, libs: SearchPaths,
                     }
                     if count > 0 && error_codes.len() > 0 {
                         let out = String::from_utf8(data.lock().unwrap().to_vec()).unwrap();
-                        error_codes = error_codes.into_iter().filter(|err| !out.contains(err)).collect();
+                        error_codes.retain(|err| !out.contains(err));
                     }
                 }
                 Ok(()) if compile_fail => panic!("test compiled while it wasn't supposed to"),