diff --git a/src/app/parser.rs b/src/app/parser.rs
index 1cb3ca4f..bf04c245 100644
--- a/src/app/parser.rs
+++ b/src/app/parser.rs
@@ -427,7 +427,7 @@ impl<'a, 'b> Parser<'a, 'b> where 'a: 'b {
             debug!("Starts new arg...");
             let starts_new_arg = if arg_os.starts_with(b"-") {
                 sdebugln!("Yes");
-                !(arg_os.len() == 1)
+                !(arg_os.len_() == 1)
             } else {
                 sdebugln!("No");
                 false
@@ -448,7 +448,7 @@ impl<'a, 'b> Parser<'a, 'b> where 'a: 'b {
                     }
                 }
                 if arg_os.starts_with(b"--") {
-                    if arg_os.len() == 2 {
+                    if arg_os.len_() == 2 {
                         // The user has passed '--' which means only positional args follow no matter
                         // what they start with
                         pos_only = true;
@@ -457,7 +457,7 @@ impl<'a, 'b> Parser<'a, 'b> where 'a: 'b {
 
                     needs_val_of = try!(self.parse_long_arg(matcher, &arg_os));
                     continue;
-                } else if arg_os.starts_with(b"-") && arg_os.len() != 1 {
+                } else if arg_os.starts_with(b"-") && arg_os.len_() != 1 {
                     needs_val_of = try!(self.parse_short_arg(matcher, &arg_os));
                     if !(needs_val_of.is_none() && self.is_set(AppSettings::AllowLeadingHyphen)) {
                         continue;
@@ -972,7 +972,7 @@ impl<'a, 'b> Parser<'a, 'b> where 'a: 'b {
         debug!("Checking for val...");
         if let Some(fv) = val {
             let v = fv.trim_left_matches(b'=');
-            if !opt.is_set(ArgSettings::EmptyValues) && v.len() == 0 {
+            if !opt.is_set(ArgSettings::EmptyValues) && v.len_() == 0 {
                 sdebugln!("Found Empty - Error");
                 return Err(Error::empty_value(opt, &*self.create_current_usage(matcher)));
             }
@@ -1043,7 +1043,7 @@ impl<'a, 'b> Parser<'a, 'b> where 'a: 'b {
             }
         }
         if !arg.is_set(ArgSettings::EmptyValues) &&
-            val.is_empty() &&
+            val.is_empty_() &&
             matcher.contains(&*arg.name()) {
             return Err(Error::empty_value(arg, &*self.create_current_usage(matcher)));
         }
diff --git a/src/osstringext.rs b/src/osstringext.rs
index 5e179ba6..b8fb72ad 100644
--- a/src/osstringext.rs
+++ b/src/osstringext.rs
@@ -17,9 +17,9 @@ pub trait OsStrExt2 {
     fn split_at_byte(&self, b: u8) -> (&OsStr, &OsStr);
     fn split_at(&self, i: usize) -> (&OsStr, &OsStr);
     fn trim_left_matches(&self, b: u8) -> &OsStr;
-    fn len(&self) -> usize;
+    fn len_(&self) -> usize;
     fn contains_byte(&self, b: u8) -> bool;
-    fn is_empty(&self) -> bool;
+    fn is_empty_(&self) -> bool;
     fn split(&self, b: u8) -> OsSplit;
 }
 
@@ -39,7 +39,7 @@ impl OsStrExt2 for OsStr {
         self.as_bytes().starts_with(s)
     }
 
-    fn is_empty(&self) -> bool {
+    fn is_empty_(&self) -> bool {
         self.as_bytes().is_empty()
     }
 
@@ -54,7 +54,7 @@ impl OsStrExt2 for OsStr {
         for (i, b) in self.as_bytes().iter().enumerate() {
             if b == &byte { return (&OsStr::from_bytes(&self.as_bytes()[..i]), &OsStr::from_bytes(&self.as_bytes()[i+1..])); }
         }
-        (&*self, &OsStr::from_bytes(&self.as_bytes()[self.len()..self.len()]))
+        (&*self, &OsStr::from_bytes(&self.as_bytes()[self.len_()..self.len_()]))
     }
 
     fn trim_left_matches(&self, byte: u8) -> &OsStr {
@@ -68,7 +68,7 @@ impl OsStrExt2 for OsStr {
         (&OsStr::from_bytes(&self.as_bytes()[..i]), &OsStr::from_bytes(&self.as_bytes()[i..]))
     }
 
-    fn len(&self) -> usize {
+    fn len_(&self) -> usize {
         self.as_bytes().len()
     }