diff --git a/rustfmt.toml b/rustfmt.toml
index ad54acc..a1ffd27 100644
--- a/rustfmt.toml
+++ b/rustfmt.toml
@@ -1,2 +1 @@
-edition = "2018"
 max_width = 79
diff --git a/src/lib.rs b/src/lib.rs
index 95f5afc..b20e198 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -160,19 +160,16 @@ macro_rules! if_raw {
     };
 }
 
+#[cfg_attr(windows, path = "windows/mod.rs")]
+#[cfg_attr(not(windows), path = "common/mod.rs")]
+mod imp;
+
 mod error;
 
 if_raw! {
     pub mod raw;
 }
 
-#[cfg(not(windows))]
-#[path = "common/mod.rs"]
-mod imp;
-#[cfg(windows)]
-#[path = "windows/mod.rs"]
-mod imp;
-
 /// The error that occurs when a byte sequence is not representable in the
 /// platform encoding.
 ///
diff --git a/src/windows/mod.rs b/src/windows/mod.rs
index 56bee94..8582b7f 100644
--- a/src/windows/mod.rs
+++ b/src/windows/mod.rs
@@ -61,7 +61,7 @@ impl OsStringBytes for OsString {
 
     #[inline]
     fn into_vec(self) -> Vec<u8> {
-        OsStrBytes::to_bytes(self.as_os_str()).into_owned()
+        OsStrBytes::to_bytes(&*self).into_owned()
     }
 }
 
diff --git a/src/windows/wtf8/convert.rs b/src/windows/wtf8/convert.rs
index 46a62b6..656fbb9 100644
--- a/src/windows/wtf8/convert.rs
+++ b/src/windows/wtf8/convert.rs
@@ -112,15 +112,14 @@ where
 
         self.iter.next().map(|code_point| {
             code_point.map(|code_point| {
-                if let Some(offset) =
-                    code_point.checked_sub(MIN_SURROGATE_CODE)
-                {
-                    self.surrogate =
-                        Some((offset & 0x3FF) as u16 | MIN_LOW_SURROGATE);
-                    (offset >> 10) as u16 | MIN_HIGH_SURROGATE
-                } else {
-                    code_point as u16
-                }
+                code_point
+                    .checked_sub(MIN_SURROGATE_CODE)
+                    .map(|offset| {
+                        self.surrogate =
+                            Some((offset & 0x3FF) as u16 | MIN_LOW_SURROGATE);
+                        (offset >> 10) as u16 | MIN_HIGH_SURROGATE
+                    })
+                    .unwrap_or(code_point as u16)
             })
         })
     }
diff --git a/src/windows/wtf8/string.rs b/src/windows/wtf8/string.rs
index da6bbf4..05e155a 100644
--- a/src/windows/wtf8/string.rs
+++ b/src/windows/wtf8/string.rs
@@ -42,10 +42,6 @@ pub(in super::super) fn starts_with(
     string: &[u8],
     mut prefix: &[u8],
 ) -> Option<bool> {
-    if prefix.is_empty() {
-        return Some(true);
-    }
-
     if let Some(&byte) = string.get(prefix.len()) {
         if is_continuation(byte) {
             let index = prefix.len().checked_sub(SURROGATE_LENGTH)?;
diff --git a/tests/common.rs b/tests/common.rs
index abb3856..2bdaf4d 100644
--- a/tests/common.rs
+++ b/tests/common.rs
@@ -57,7 +57,7 @@ pub(crate) fn test_bytes(string: &[u8]) -> Result<(), EncodingError> {
 pub(crate) fn test_vec(string: &[u8]) -> Result<(), EncodingError> {
     let os_string = from_vec(string.to_vec())?;
     assert_eq!(string.len(), os_string.len());
-    assert_eq!(string, os_string.into_vec().as_slice());
+    assert_eq!(string, &*os_string.into_vec());
     Ok(())
 }
 
@@ -72,5 +72,5 @@ pub(crate) fn test_utf8_vec(string: &str) {
     let os_string = string.to_string().into();
     let string = string.as_bytes();
     assert_eq!(Ok(&os_string), from_vec(string.to_vec()).as_ref());
-    assert_eq!(string, os_string.into_vec().as_slice());
+    assert_eq!(string, &*os_string.into_vec());
 }
diff --git a/tests/random.rs b/tests/random.rs
index 9537fee..d68ad26 100644
--- a/tests/random.rs
+++ b/tests/random.rs
@@ -67,7 +67,7 @@ fn test_random_vec() -> Result<(), getrandom::Error> {
 
 #[test]
 fn test_lossless() -> Result<(), getrandom::Error> {
-    for _ in 1..ITERATIONS {
+    for _ in 0..ITERATIONS {
         let mut string = vec![0; SMALL_LENGTH];
         getrandom(&mut string)?;
         if let Ok(os_string) = OsStr::from_bytes(&string) {
@@ -95,7 +95,7 @@ fn test_raw() -> Result<(), getrandom::Error> {
         };
     }
 
-    for _ in 1..ITERATIONS {
+    for _ in 0..ITERATIONS {
         let mut string = random_os_string(SMALL_LENGTH)?;
         let prefix = string.to_bytes().into_owned();
         let suffix = random_os_string(SMALL_LENGTH)?;