diff --git a/src/bootstrap/builder.rs b/src/bootstrap/builder.rs
index 2d15cae4c0281..9300b94156acb 100644
--- a/src/bootstrap/builder.rs
+++ b/src/bootstrap/builder.rs
@@ -806,7 +806,7 @@ impl<'a> Builder<'a> {
             );
         }
 
-        if [Mode::ToolRustc, Mode::ToolStd, Mode::ToolTest].iter().any(|m| &mode == m) {
+        if mode.is_tool() {
             // Tools like cargo and rls don't get debuginfo by default right now, but this can be
             // enabled in the config.  Adding debuginfo makes them several times larger.
             if self.config.rust_debuginfo_tools {
@@ -1012,7 +1012,7 @@ impl<'a> Builder<'a> {
         // be resolved because MinGW has the import library. The downside is we
         // don't get newer functions from Windows, but we don't use any of them
         // anyway.
-        if ![Mode::ToolRustc, Mode::ToolStd, Mode::ToolTest].iter().any(|m| &mode == m) {
+        if !mode.is_tool() {
             cargo.env("WINAPI_NO_BUNDLED_LIBRARIES", "1");
         }
 
diff --git a/src/bootstrap/check.rs b/src/bootstrap/check.rs
index 476a85c9a49ad..b3ccb3cc3c926 100644
--- a/src/bootstrap/check.rs
+++ b/src/bootstrap/check.rs
@@ -219,7 +219,7 @@ impl Step for Rustdoc {
 
         let mut cargo = prepare_tool_cargo(builder,
                                            compiler,
-                                           Mode::Rustc,
+                                           Mode::ToolRustc,
                                            target,
                                            "check",
                                            "src/tools/rustdoc");
diff --git a/src/bootstrap/dist.rs b/src/bootstrap/dist.rs
index 3dbeea307c28c..7341137e20d72 100644
--- a/src/bootstrap/dist.rs
+++ b/src/bootstrap/dist.rs
@@ -953,7 +953,7 @@ impl Step for PlainSourceTarball {
             if !has_cargo_vendor {
                 let mut cmd = builder.cargo(
                     builder.compiler(0, builder.config.build),
-                    Mode::Tool,
+                    Mode::ToolRustc,
                     builder.config.build,
                     "install"
                 );
diff --git a/src/bootstrap/doc.rs b/src/bootstrap/doc.rs
index 4aa42a7522681..19599b33ebe26 100644
--- a/src/bootstrap/doc.rs
+++ b/src/bootstrap/doc.rs
@@ -799,13 +799,15 @@ impl Step for Rustdoc {
         builder.ensure(tool::Rustdoc { host: compiler.host });
 
         // Symlink compiler docs to the output directory of rustdoc documentation.
-        let out_dir = builder.stage_out(compiler, Mode::Tool).join(target).join("doc");
+        let out_dir = builder.stage_out(compiler, Mode::ToolRustc).join(target).join("doc");
         t!(fs::create_dir_all(&out_dir));
         builder.clear_if_dirty(&out, &rustdoc);
         t!(symlink_dir_force(&builder.config, &out, &out_dir));
 
         // Build cargo command.
-        let mut cargo = prepare_tool_cargo(builder, compiler, target, "doc", "src/tools/rustdoc");
+        let mut cargo = prepare_tool_cargo(
+            builder, compiler, Mode::ToolRustc, target, "doc", "src/tools/rustdoc");
+
         cargo.env("RUSTDOCFLAGS", "--document-private-items");
         builder.run(&mut cargo);
     }
diff --git a/src/bootstrap/lib.rs b/src/bootstrap/lib.rs
index 7576505e29508..d16d7a520659b 100644
--- a/src/bootstrap/lib.rs
+++ b/src/bootstrap/lib.rs
@@ -324,6 +324,15 @@ pub enum Mode {
     ToolRustc,
 }
 
+impl Mode {
+    pub fn is_tool(&self) -> bool {
+        match self {
+            Mode::ToolStd | Mode::ToolTest | Mode::ToolRustc => true,
+            _ => false
+        }
+    }
+}
+
 impl Build {
     /// Creates a new set of build configuration from the `flags` on the command
     /// line and the filesystem `config`.
diff --git a/src/bootstrap/test.rs b/src/bootstrap/test.rs
index b08227388bb61..a0b6222421d71 100644
--- a/src/bootstrap/test.rs
+++ b/src/bootstrap/test.rs
@@ -1729,7 +1729,7 @@ impl Step for CrateRustdoc {
 
         let mut cargo = tool::prepare_tool_cargo(builder,
                                                  compiler,
-                                                 Mode::Rustc,
+                                                 Mode::ToolRustc,
                                                  target,
                                                  test_kind.subcommand(),
                                                  "src/tools/rustdoc");