diff --git a/src/app/parser.rs b/src/app/parser.rs
index 017fb4075aa..144418bf6fc 100644
--- a/src/app/parser.rs
+++ b/src/app/parser.rs
@@ -234,7 +234,8 @@ impl<'a, 'b> Parser<'a, 'b>
 
     pub fn add_subcommand(&mut self, mut subcmd: App<'a, 'b>) {
         debugln!("Parser::add_subcommand;");
-        debugln!("Parser::add_subcommand: Term width...{:?}", self.meta.term_w);
+        debugln!("Parser::add_subcommand: Term width...{:?}",
+                 self.meta.term_w);
         subcmd.p.meta.term_w = self.meta.term_w;
         debug!("Parser::add_subcommand: Is help...");
         if subcmd.p.meta.name == "help" {
@@ -256,8 +257,10 @@ impl<'a, 'b> Parser<'a, 'b>
                 let vsc = self.settings.is_set(AppSettings::VersionlessSubcommands);
                 let gv = self.settings.is_set(AppSettings::GlobalVersion);
 
-                debugln!("Parser::propogate_settings:iter: VersionlessSubcommands set...{:?}", vsc);
-                debugln!("Parser::propogate_settings:iter: GlobalVersion set...{:?}", gv);
+                debugln!("Parser::propogate_settings:iter: VersionlessSubcommands set...{:?}",
+                         vsc);
+                debugln!("Parser::propogate_settings:iter: GlobalVersion set...{:?}",
+                         gv);
 
                 if vsc {
                     sc.p.settings.set(AppSettings::DisableVersion);
@@ -438,7 +441,7 @@ impl<'a, 'b> Parser<'a, 'b>
                         if grp.required {
                             // if it's part of a required group we don't want to count it
                             continue 'outer;
-                        } 
+                        }
                     }
                 }
             }
@@ -1540,7 +1543,9 @@ impl<'a, 'b> Parser<'a, 'b>
         }
         if let Some(vtor) = arg.validator_os() {
             if let Err(e) = vtor(val) {
-                return Err(Error::value_validation(Some(arg), (*e).to_string_lossy().to_string(), self.color()));
+                return Err(Error::value_validation(Some(arg),
+                                                   (*e).to_string_lossy().to_string(),
+                                                   self.color()));
             }
         }
         if matcher.needs_more_vals(arg) {
@@ -1703,6 +1708,10 @@ impl<'a, 'b> Parser<'a, 'b>
                                                  self.color()));
             }
         }
+        // Issue 665 (https://github.com/kbknapp/clap-rs/issues/665)
+        if a.takes_value() && !a.is_set(ArgSettings::EmptyValues) && ma.vals.is_empty() {
+            return Err(Error::empty_value(a, &*self.create_current_usage(matcher), self.color()));
+        }
         Ok(())
     }
 
@@ -1731,16 +1740,15 @@ impl<'a, 'b> Parser<'a, 'b>
         let c = Colorizer {
             use_stderr: true,
             when: self.color(),
-        };        
-	let mut reqs = self.required.iter().map(|&r| &*r).collect::<Vec<_>>();
+        };
+        let mut reqs = self.required.iter().map(|&r| &*r).collect::<Vec<_>>();
         reqs.retain(|n| !matcher.contains(n));
         reqs.dedup();
         Err(Error::missing_required_argument(&*self.get_required_from(&self.required[..],
                                                                     Some(matcher))
                                                  .iter()
                                                  .fold(String::new(), |acc, s| {
-                                                     acc +
-                                                     &format!("\n    {}", c.error(s))[..]
+                                                     acc + &format!("\n    {}", c.error(s))[..]
                                                  }),
                                              &*self.create_current_usage(matcher),
                                              self.color()))
diff --git a/tests/opts.rs b/tests/opts.rs
index 2cdd894ea94..b44bd2fd9ac 100644
--- a/tests/opts.rs
+++ b/tests/opts.rs
@@ -8,7 +8,7 @@ use clap::{App, Arg, ErrorKind};
 #[test]
 fn stdin_char() {
     let r = App::new("opts")
-        .arg( Arg::from_usage("-f [flag] 'some flag'") )
+        .arg(Arg::from_usage("-f [flag] 'some flag'"))
         .get_matches_from_safe(vec!["", "-f", "-"]);
     assert!(r.is_ok());
     let m = r.unwrap();
@@ -19,10 +19,8 @@ fn stdin_char() {
 #[test]
 fn opts_using_short() {
     let r = App::new("opts")
-        .args(&[
-            Arg::from_usage("-f [flag] 'some flag'"),
-            Arg::from_usage("-c [color] 'some other flag'")
-            ])
+        .args(&[Arg::from_usage("-f [flag] 'some flag'"),
+                Arg::from_usage("-c [color] 'some other flag'")])
         .get_matches_from_safe(vec!["", "-f", "some", "-c", "other"]);
     assert!(r.is_ok());
     let m = r.unwrap();
@@ -35,38 +33,50 @@ fn opts_using_short() {
 #[test]
 fn lots_o_vals() {
     let r = App::new("opts")
-        .arg(
-            Arg::from_usage("-o [opt]... 'some opt'"),
-            )
-        .get_matches_from_safe(vec!["", "-o",
-            "some", "some", "some", "some", "some", "some", "some", "some", "some", "some", "some",
-            "some", "some", "some", "some", "some", "some", "some", "some", "some", "some", "some",
-            "some", "some", "some", "some", "some", "some", "some", "some", "some", "some", "some",
-            "some", "some", "some", "some", "some", "some", "some", "some", "some", "some", "some",
-            "some", "some", "some", "some", "some", "some", "some", "some", "some", "some", "some",
-            "some", "some", "some", "some", "some", "some", "some", "some", "some", "some", "some",
-            "some", "some", "some", "some", "some", "some", "some", "some", "some", "some", "some",
-            "some", "some", "some", "some", "some", "some", "some", "some", "some", "some", "some",
-            "some", "some", "some", "some", "some", "some", "some", "some", "some", "some", "some",
-            "some", "some", "some", "some", "some", "some", "some", "some", "some", "some", "some",
-            "some", "some", "some", "some", "some", "some", "some", "some", "some", "some", "some",
-            "some", "some", "some", "some", "some", "some", "some", "some", "some", "some", "some",
-            "some", "some", "some", "some", "some", "some", "some", "some", "some", "some", "some",
-            "some", "some", "some", "some", "some", "some", "some", "some", "some", "some", "some",
-            "some", "some", "some", "some", "some", "some", "some", "some", "some", "some", "some",
-            "some", "some", "some", "some", "some", "some", "some", "some", "some", "some", "some",
-            "some", "some", "some", "some", "some", "some", "some", "some", "some", "some", "some",
-            "some", "some", "some", "some", "some", "some", "some", "some", "some", "some", "some",
-            "some", "some", "some", "some", "some", "some", "some", "some", "some", "some", "some",
-            "some", "some", "some", "some", "some", "some", "some", "some", "some", "some", "some",
-            "some", "some", "some", "some", "some", "some", "some", "some", "some", "some", "some",
-            "some", "some", "some", "some", "some", "some", "some", "some", "some", "some", "some",
-            "some", "some", "some", "some", "some", "some", "some", "some", "some", "some", "some",
-            "some", "some", "some", "some", "some", "some", "some", "some", "some", "some", "some",
-            "some", "some", "some", "some", "some", "some", "some", "some", "some", "some", "some",
-            "some", "some", "some", "some", "some", "some", "some", "some", "some", "some", "some",
-            "some", "some", "some", "some", "some", "some", "some", "some", "some", "some", "some",
-            ]);
+        .arg(Arg::from_usage("-o [opt]... 'some opt'"))
+        .get_matches_from_safe(vec!["", "-o", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some", "some", "some", "some",
+                                    "some", "some", "some", "some"]);
     assert!(r.is_ok());
     let m = r.unwrap();
     assert!(m.is_present("o"));
@@ -76,10 +86,8 @@ fn lots_o_vals() {
 #[test]
 fn opts_using_long_space() {
     let r = App::new("opts")
-        .args(&[
-            Arg::from_usage("--flag [flag] 'some flag'"),
-            Arg::from_usage("--color [color] 'some other flag'")
-            ])
+        .args(&[Arg::from_usage("--flag [flag] 'some flag'"),
+                Arg::from_usage("--color [color] 'some other flag'")])
         .get_matches_from_safe(vec!["", "--flag", "some", "--color", "other"]);
     assert!(r.is_ok());
     let m = r.unwrap();
@@ -97,16 +105,15 @@ fn opts_with_empty_values() {
     assert!(r.is_ok());
     let m = r.unwrap();
     assert!(m.is_present("flag"));
-    assert_eq!(m.values_of("flag").unwrap().collect::<Vec<_>>(), ["", "test"]);
+    assert_eq!(m.values_of("flag").unwrap().collect::<Vec<_>>(),
+               ["", "test"]);
 }
 
 #[test]
 fn opts_using_long_equals() {
     let r = App::new("opts")
-        .args(&[
-            Arg::from_usage("--flag [flag] 'some flag'"),
-            Arg::from_usage("--color [color] 'some other flag'")
-            ])
+        .args(&[Arg::from_usage("--flag [flag] 'some flag'"),
+                Arg::from_usage("--color [color] 'some other flag'")])
         .get_matches_from_safe(vec!["", "--flag=some", "--color=other"]);
     assert!(r.is_ok());
     let m = r.unwrap();
@@ -119,10 +126,8 @@ fn opts_using_long_equals() {
 #[test]
 fn opts_using_mixed() {
     let r = App::new("opts")
-        .args(&[
-            Arg::from_usage("-f, --flag [flag] 'some flag'"),
-            Arg::from_usage("-c, --color [color] 'some other flag'")
-            ])
+        .args(&[Arg::from_usage("-f, --flag [flag] 'some flag'"),
+                Arg::from_usage("-c, --color [color] 'some other flag'")])
         .get_matches_from_safe(vec!["", "-f", "some", "--color", "other"]);
     assert!(r.is_ok());
     let m = r.unwrap();
@@ -135,10 +140,8 @@ fn opts_using_mixed() {
 #[test]
 fn opts_using_mixed2() {
     let r = App::new("opts")
-        .args(&[
-            Arg::from_usage("-f, --flag [flag] 'some flag'"),
-            Arg::from_usage("-c, --color [color] 'some other flag'")
-            ])
+        .args(&[Arg::from_usage("-f, --flag [flag] 'some flag'"),
+                Arg::from_usage("-c, --color [color] 'some other flag'")])
         .get_matches_from_safe(vec!["", "--flag=some", "-c", "other"]);
     assert!(r.is_ok());
     let m = r.unwrap();
@@ -151,8 +154,7 @@ fn opts_using_mixed2() {
 #[test]
 fn default_values_user_value() {
     let r = App::new("df")
-        .arg( Arg::from_usage("-o [opt] 'some opt'")
-            .default_value("default"))
+        .arg(Arg::from_usage("-o [opt] 'some opt'").default_value("default"))
         .get_matches_from_safe(vec!["", "-o", "value"]);
     assert!(r.is_ok());
     let m = r.unwrap();
@@ -163,8 +165,8 @@ fn default_values_user_value() {
 #[test]
 fn multiple_vals_pos_arg_equals() {
     let r = App::new("mvae")
-        .arg( Arg::from_usage("-o [opt]... 'some opt'") )
-        .arg( Arg::from_usage("[file] 'some file'") )
+        .arg(Arg::from_usage("-o [opt]... 'some opt'"))
+        .arg(Arg::from_usage("[file] 'some file'"))
         .get_matches_from_safe(vec!["", "-o=1", "some"]);
     assert!(r.is_ok());
     let m = r.unwrap();
@@ -177,8 +179,8 @@ fn multiple_vals_pos_arg_equals() {
 #[test]
 fn multiple_vals_pos_arg_delim() {
     let r = App::new("mvae")
-        .arg( Arg::from_usage("-o [opt]... 'some opt'") )
-        .arg( Arg::from_usage("[file] 'some file'") )
+        .arg(Arg::from_usage("-o [opt]... 'some opt'"))
+        .arg(Arg::from_usage("[file] 'some file'"))
         .get_matches_from_safe(vec!["", "-o", "1,2", "some"]);
     assert!(r.is_ok());
     let m = r.unwrap();
@@ -191,8 +193,8 @@ fn multiple_vals_pos_arg_delim() {
 #[test]
 fn require_delims_no_delim() {
     let r = App::new("mvae")
-        .arg( Arg::from_usage("-o [opt]... 'some opt'").require_delimiter(true) )
-        .arg( Arg::from_usage("[file] 'some file'") )
+        .arg(Arg::from_usage("-o [opt]... 'some opt'").require_delimiter(true))
+        .arg(Arg::from_usage("[file] 'some file'"))
         .get_matches_from_safe(vec!["mvae", "-o", "1", "2", "some"]);
     assert!(r.is_err());
     let err = r.unwrap_err();
@@ -202,8 +204,8 @@ fn require_delims_no_delim() {
 #[test]
 fn require_delims() {
     let r = App::new("mvae")
-        .arg( Arg::from_usage("-o [opt]... 'some opt'").require_delimiter(true) )
-        .arg( Arg::from_usage("[file] 'some file'") )
+        .arg(Arg::from_usage("-o [opt]... 'some opt'").require_delimiter(true))
+        .arg(Arg::from_usage("[file] 'some file'"))
         .get_matches_from_safe(vec!["", "-o", "1,2", "some"]);
     assert!(r.is_ok());
     let m = r.unwrap();
@@ -216,7 +218,7 @@ fn require_delims() {
 #[test]
 fn leading_hyphen_pass() {
     let r = App::new("mvae")
-        .arg( Arg::from_usage("-o [opt]... 'some opt'").allow_hyphen_values(true))
+        .arg(Arg::from_usage("-o [opt]... 'some opt'").allow_hyphen_values(true))
         .get_matches_from_safe(vec!["", "-o", "-2", "3"]);
     assert!(r.is_ok());
     let m = r.unwrap();
@@ -227,7 +229,7 @@ fn leading_hyphen_pass() {
 #[test]
 fn leading_hyphen_fail() {
     let r = App::new("mvae")
-        .arg( Arg::from_usage("-o [opt] 'some opt'"))
+        .arg(Arg::from_usage("-o [opt] 'some opt'"))
         .get_matches_from_safe(vec!["", "-o", "-2"]);
     assert!(r.is_err());
     let m = r.unwrap_err();
@@ -237,7 +239,7 @@ fn leading_hyphen_fail() {
 #[test]
 fn leading_hyphen_with_flag_after() {
     let r = App::new("mvae")
-        .arg( Arg::from_usage("-o [opt]... 'some opt'").allow_hyphen_values(true))
+        .arg(Arg::from_usage("-o [opt]... 'some opt'").allow_hyphen_values(true))
         .arg_from_usage("-f 'some flag'")
         .get_matches_from_safe(vec!["", "-o", "-2", "-f"]);
     assert!(r.is_ok());
@@ -250,7 +252,7 @@ fn leading_hyphen_with_flag_after() {
 #[test]
 fn leading_hyphen_with_flag_before() {
     let r = App::new("mvae")
-        .arg( Arg::from_usage("-o [opt]... 'some opt'").allow_hyphen_values(true))
+        .arg(Arg::from_usage("-o [opt]... 'some opt'").allow_hyphen_values(true))
         .arg_from_usage("-f 'some flag'")
         .get_matches_from_safe(vec!["", "-f", "-o", "-2"]);
     assert!(r.is_ok());
@@ -263,7 +265,7 @@ fn leading_hyphen_with_flag_before() {
 #[test]
 fn leading_hyphen_with_only_pos_follows() {
     let r = App::new("mvae")
-        .arg( Arg::from_usage("-o [opt]... 'some opt'").allow_hyphen_values(true))
+        .arg(Arg::from_usage("-o [opt]... 'some opt'").allow_hyphen_values(true))
         .arg_from_usage("[arg] 'some arg'")
         .get_matches_from_safe(vec!["", "-o", "-2", "--", "val"]);
     assert!(r.is_ok());
@@ -276,12 +278,27 @@ fn leading_hyphen_with_only_pos_follows() {
 #[test]
 #[cfg(feature="suggestions")]
 fn did_you_mean() {
-    test::check_err_output(test::complex_app(), "clap-test --optio=foo",
-"error: Found argument '--optio' which wasn't expected, or isn't valid in this context
+    test::check_err_output(test::complex_app(),
+                           "clap-test --optio=foo",
+                           "error: Found argument '--optio' which wasn't expected, or isn't valid in this context
 \tDid you mean --option?
 
 USAGE:
     clap-test --option <opt>...
 
-For more information try --help", true);
+For more information try --help",
+                           true);
 }
+
+#[test]
+fn issue_665() {
+    let res = App::new("tester")
+        .arg_from_usage("-v, --reroll-count=[N] 'Mark the patch series as PATCH vN'")
+        .arg(Arg::from_usage(
+"--subject-prefix [Subject-Prefix] 'Use [Subject-Prefix] instead of the standard [PATCH] prefix'")
+            .empty_values(false))
+        .get_matches_from_safe(vec!["test", "--subject-prefix", "-v", "2"]);
+
+    assert!(res.is_err());
+    assert_eq!(res.unwrap_err().kind, ErrorKind::EmptyValue);
+}
\ No newline at end of file