diff --git a/src/unit/mod.rs b/src/unit/mod.rs
index 7f6dde5..b104035 100644
--- a/src/unit/mod.rs
+++ b/src/unit/mod.rs
@@ -155,45 +155,45 @@ impl Unit {
     }
 }
 
-impl From<&String> for Unit {
-    fn from(unit: &String) -> Self {
-        match unit.to_ascii_lowercase().as_bytes() {
-            b"px" => Unit::Px,
-            b"mm" => Unit::Mm,
-            b"in" => Unit::In,
-            b"cm" => Unit::Cm,
-            b"q" => Unit::Q,
-            b"pt" => Unit::Pt,
-            b"pc" => Unit::Pc,
-            b"em" => Unit::Em,
-            b"rem" => Unit::Rem,
-            b"lh" => Unit::Lh,
-            b"%" => Unit::Percent,
-            b"ex" => Unit::Ex,
-            b"ch" => Unit::Ch,
-            b"cap" => Unit::Cap,
-            b"ic" => Unit::Ic,
-            b"rlh" => Unit::Rlh,
-            b"vw" => Unit::Vw,
-            b"vh" => Unit::Vh,
-            b"vmin" => Unit::Vmin,
-            b"vmax" => Unit::Vmax,
-            b"vi" => Unit::Vi,
-            b"vb" => Unit::Vb,
-            b"deg" => Unit::Deg,
-            b"grad" => Unit::Grad,
-            b"rad" => Unit::Rad,
-            b"turn" => Unit::Turn,
-            b"s" => Unit::S,
-            b"ms" => Unit::Ms,
-            b"hz" => Unit::Hz,
-            b"khz" => Unit::Khz,
-            b"dpi" => Unit::Dpi,
-            b"dpcm" => Unit::Dpcm,
-            b"dppx" => Unit::Dppx,
-            b"x" => Unit::X,
-            b"fr" => Unit::Fr,
-            _ => Unit::Unknown(String::from(unit)),
+impl From<String> for Unit {
+    fn from(unit: String) -> Self {
+        match unit.to_ascii_lowercase().as_str() {
+            "px" => Unit::Px,
+            "mm" => Unit::Mm,
+            "in" => Unit::In,
+            "cm" => Unit::Cm,
+            "q" => Unit::Q,
+            "pt" => Unit::Pt,
+            "pc" => Unit::Pc,
+            "em" => Unit::Em,
+            "rem" => Unit::Rem,
+            "lh" => Unit::Lh,
+            "%" => Unit::Percent,
+            "ex" => Unit::Ex,
+            "ch" => Unit::Ch,
+            "cap" => Unit::Cap,
+            "ic" => Unit::Ic,
+            "rlh" => Unit::Rlh,
+            "vw" => Unit::Vw,
+            "vh" => Unit::Vh,
+            "vmin" => Unit::Vmin,
+            "vmax" => Unit::Vmax,
+            "vi" => Unit::Vi,
+            "vb" => Unit::Vb,
+            "deg" => Unit::Deg,
+            "grad" => Unit::Grad,
+            "rad" => Unit::Rad,
+            "turn" => Unit::Turn,
+            "s" => Unit::S,
+            "ms" => Unit::Ms,
+            "hz" => Unit::Hz,
+            "khz" => Unit::Khz,
+            "dpi" => Unit::Dpi,
+            "dpcm" => Unit::Dpcm,
+            "dppx" => Unit::Dppx,
+            "x" => Unit::X,
+            "fr" => Unit::Fr,
+            _ => Unit::Unknown(unit),
         }
     }
 }
@@ -237,7 +237,7 @@ impl fmt::Display for Unit {
             Unit::X => write!(f, "x"),
             Unit::Fr => write!(f, "fr"),
             Unit::Unknown(s) => write!(f, "{}", s),
-            Unit::None => write!(f, ""),
+            Unit::None => Ok(()),
             Unit::Mul(u) => write!(
                 f,
                 "{}",
diff --git a/src/value/parse.rs b/src/value/parse.rs
index 605fc72..720abed 100644
--- a/src/value/parse.rs
+++ b/src/value/parse.rs
@@ -651,7 +651,7 @@ impl Value {
                                 Err(e) => return Some(Err(e)),
                             };
                             span = span.merge(u.span);
-                            Unit::from(&u.node)
+                            Unit::from(u.node)
                         }
                         '%' => {
                             span = span.merge(toks.next().unwrap().pos());