diff --git a/src/lib.rs b/src/lib.rs
index 6e4ba7aa85..b1ba1b1b88 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1580,18 +1580,15 @@ impl Bindings {
 
     /// Write these bindings as source text to a file.
     pub fn write_to_file<P: AsRef<Path>>(&self, path: P) -> io::Result<()> {
-        {
-            let file = try!(
-                OpenOptions::new()
-                    .write(true)
-                    .truncate(true)
-                    .create(true)
-                    .open(path.as_ref())
-            );
-            self.write(Box::new(file))?;
-        }
-
-        self.rustfmt_generated_file(path.as_ref())
+        let file = try!(
+            OpenOptions::new()
+                .write(true)
+                .truncate(true)
+                .create(true)
+                .open(path.as_ref())
+        );
+        self.write(Box::new(file))?;
+        Ok(())
     }
 
     /// Write these bindings as source text to the given `Write`able.
@@ -1604,11 +1601,19 @@ impl Bindings {
             writer.write(line.as_bytes())?;
             writer.write("\n".as_bytes())?;
         }
+
         if !self.options.raw_lines.is_empty() {
             writer.write("\n".as_bytes())?;
         }
 
-        writer.write(self.module.as_str().as_bytes())?;
+        let bindings = self.module.as_str().to_string();
+
+        match self.rustfmt_generated_string(bindings) {
+            Ok(rustfmt_bindings) => {
+                writer.write(rustfmt_bindings.as_str().as_bytes())?;
+            },
+            Err(err) => eprintln!("{:?}", err),
+        }
         Ok(())
     }
 
@@ -1668,6 +1673,79 @@ impl Bindings {
             ))
         }
     }
+
+    /// Checks if rustfmt_bindings is set and runs rustfmt on the string
+    //fn rustfmt_generated_string(&self, source: String) -> io::Result<Option<(String, String)>> {
+    fn rustfmt_generated_string(&self, source: String) -> io::Result<String> {
+        let _t = self.context.timer("rustfmt_generated_string");
+
+        if !self.context.options().rustfmt_bindings {
+            return Ok(source);
+        }
+
+        let rustfmt = if let Ok(rustfmt) = which::which("rustfmt") {
+            rustfmt
+        } else {
+            eprintln!("warning: could not find usable rustfmt to pretty print bindings");
+            return Ok(source);
+        };
+
+        let mut cmd = if let Ok(rustup) = which::which("rustup") {
+            let mut cmd = Command::new(rustup);
+                cmd.args(&["run", "nightly", "rustfmt", "--"]);
+                cmd
+            } else {
+                Command::new(rustfmt)
+            };
+
+        cmd
+            .args(&["--write-mode=display"])
+            .stdin(Stdio::piped())
+            .stdout(Stdio::piped())
+            .stderr(Stdio::piped());
+
+        if let Some(path) = self.context
+            .options()
+            .rustfmt_configuration_file
+            .as_ref()
+            .and_then(|f| f.to_str())
+        {
+            cmd.args(&["--config-path", path]);
+        }
+
+        let mut child = cmd.spawn().expect("Failed to spawn rustfmt.");
+        let mut child_stdin = child.stdin.take().unwrap();
+        let mut child_stdout = child.stdout.take().unwrap();
+        let mut child_stderr = child.stderr.take().unwrap();
+
+        // Write to stdin in a new thread, so that we can read from stdout on this
+        // thread. This keeps the child from blocking on writing to its stdout which
+        // might block us from writing to its stdin.
+        let stdin_handle = ::std::thread::spawn(move || {
+            child_stdin.write_all(source.as_bytes())
+        });
+
+        // Read stderr on a new thread for similar reasons.
+        let stderr_handle = ::std::thread::spawn(move || {
+          let mut output = vec![];
+          io::copy(&mut child_stderr, &mut output)
+              .map(|_| String::from_utf8_lossy(&output).to_string())
+        });
+
+        let mut output = vec![];
+        io::copy(&mut child_stdout, &mut output)
+            .expect("Should copy stdout into vec OK");
+
+        // Ignore actual rustfmt status because it is often non-zero for trivial
+        // things.
+        let _ = child.wait().expect("should wait on rustfmt child OK");
+
+        stdin_handle.join();
+        let bindings = String::from_utf8(output).unwrap();
+        let child_stderr = stderr_handle.join();
+
+        Ok(bindings)
+    }
 }
 
 /// Determines whether the given cursor is in any of the files matched by the