diff --git a/src/client.rs b/src/client.rs
index 1fcc384..b384685 100644
--- a/src/client.rs
+++ b/src/client.rs
@@ -15,6 +15,12 @@ const INITIAL_TAG: u32 = 0;
 const CR: u8 = 0x0d;
 const LF: u8 = 0x0a;
 
+macro_rules! quote {
+    ($x: expr) => (
+        format!("\"{}\"", $x.replace("\\", "\\\\").replace("\"", "\\\""))
+    )
+}
+
 /// Stream to interface with the IMAP server. This interface is only for the command stream.
 #[derive(Debug)]
 pub struct Client<T: Read + Write> {
@@ -278,7 +284,7 @@ impl<T: Read + Write> Client<T> {
 
     /// Log in to the IMAP server.
     pub fn login(&mut self, username: &str, password: &str) -> Result<()> {
-        self.run_command_and_check_ok(&format!("LOGIN {} {}", username, password))
+        self.run_command_and_check_ok(&format!("LOGIN {} {}", username, quote!(password)))
     }
 
     /// Selects a mailbox
@@ -601,7 +607,7 @@ mod tests {
         let response = b"a1 OK Logged in\r\n".to_vec();
         let username = "username";
         let password = "password";
-        let command = format!("a1 LOGIN {} {}\r\n", username, password);
+        let command = format!("a1 LOGIN {} {}\r\n", username, quote!(password));
         let mock_stream = MockStream::new(response);
         let mut client = Client::new(mock_stream);
         client.login(username, password).unwrap();