diff --git a/src/rustup-cli/self_update.rs b/src/rustup-cli/self_update.rs
index 0e834d627a..1d5ec2b89e 100644
--- a/src/rustup-cli/self_update.rs
+++ b/src/rustup-cli/self_update.rs
@@ -369,6 +369,7 @@ fn do_pre_install_sanity_checks() -> Result<()> {
 // If the user is trying to install with sudo, on some systems this will
 // result in writing root-owned files to the user's home directory, because
 // sudo is configured not to change $HOME. Don't let that bogosity happen.
+#[allow(dead_code)]
 fn do_anti_sudo_check(no_prompt: bool) -> Result<()> {
     #[cfg(unix)]
     #[inline(never)] // FIXME #679. Mysterious crashes on OS X 10.10+
diff --git a/src/rustup/toolchain.rs b/src/rustup/toolchain.rs
index d862b390c7..9d351a54e6 100644
--- a/src/rustup/toolchain.rs
+++ b/src/rustup/toolchain.rs
@@ -20,6 +20,7 @@ use std::env;
 
 use url::Url;
 
+/// A fully resolved reference to a toolchain which may or may not exist
 pub struct Toolchain<'a> {
     cfg: &'a Cfg,
     name: String,
@@ -276,8 +277,14 @@ impl<'a> Toolchain<'a> {
             return Err(ErrorKind::ToolchainNotInstalled(self.name.to_owned()).into());
         }
 
-        let bin_path = &self.path.join("bin").join(binary.as_ref());
-        let mut cmd = Command::new(bin_path);
+        // Assume this binary exists within the current toolchain
+        let bin_path = self.path.join("bin").join(binary.as_ref());
+        let mut cmd = Command::new(if utils::is_file(&bin_path) {
+            &bin_path
+        } else {
+            // If not, let the OS try to resolve it globally for us
+            Path::new(&binary)
+        });
         self.set_env(&mut cmd);
         Ok(cmd)
     }
diff --git a/tests/cli-misc.rs b/tests/cli-misc.rs
index ce536f4f9f..0584420493 100644
--- a/tests/cli-misc.rs
+++ b/tests/cli-misc.rs
@@ -283,6 +283,19 @@ fn custom_toolchain_cargo_fallback_run() {
     });
 }
 
+#[test]
+fn rustup_run_searches_path() {
+    setup(&|config| {
+        #[cfg(windows)]
+        let hello_cmd = &["rustup", "run", "nightly", "cmd", "/C", "echo hello"];
+        #[cfg(not(windows))]
+        let hello_cmd = &["rustup", "run", "nightly", "sh", "-c", "echo hello"];
+
+        expect_ok(config, &["rustup", "default", "nightly"]);
+        expect_stdout_ok(config, hello_cmd, "hello");
+    });
+}
+
 #[test]
 fn multirust_env_compat() {
     setup(&|config| {