diff --git a/src/lib.rs b/src/lib.rs
index dc40670a..f708cc70 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -27257,9 +27257,23 @@ mod tests {
       ".foo{filter:url(filters.svg#filter-id)}",
     );
     minify_test(".foo { filter: blur(5px); }", ".foo{filter:blur(5px)}");
-    minify_test(".foo { filter: blur(0px); }", ".foo{filter:blur()}");
+    minify_test(".foo { filter: blur(0px); }", ".foo{filter:blur(0)}");
+    minify_test(".foo { filter: brightness(0.520); }", ".foo{filter:brightness(.52)}");
     minify_test(".foo { filter: brightness(10%); }", ".foo{filter:brightness(10%)}");
-    minify_test(".foo { filter: brightness(100%); }", ".foo{filter:brightness()}");
+    minify_test(".foo { filter: brightness(100%); }", ".foo{filter:brightness(100%)}");
+    minify_test(".foo { filter: brightness(1); }", ".foo{filter:brightness(1)}");
+    minify_test(".foo { filter: contrast(100%); }", ".foo{filter:contrast(100%)}");
+    minify_test(".foo { filter: contrast(1); }", ".foo{filter:contrast(1)}");
+    minify_test(".foo { filter: grayscale(100%); }", ".foo{filter:grayscale(100%)}");
+    minify_test(".foo { filter: grayscale(1); }", ".foo{filter:grayscale(1)}");
+    minify_test(".foo { filter: invert(100%); }", ".foo{filter:invert(100%)}");
+    minify_test(".foo { filter: invert(1); }", ".foo{filter:invert(1)}");
+    minify_test(".foo { filter: opacity(100%); }", ".foo{filter:opacity(100%)}");
+    minify_test(".foo { filter: opacity(1); }", ".foo{filter:opacity(1)}");
+    minify_test(".foo { filter: saturate(100%); }", ".foo{filter:saturate(100%)}");
+    minify_test(".foo { filter: saturate(1); }", ".foo{filter:saturate(1)}");
+    minify_test(".foo { filter: sepia(100%); }", ".foo{filter:sepia(100%)}");
+    minify_test(".foo { filter: sepia(1); }", ".foo{filter:sepia(1)}");
     minify_test(
       ".foo { filter: drop-shadow(16px 16px 20px yellow); }",
       ".foo{filter:drop-shadow(16px 16px 20px #ff0)}",
@@ -27268,7 +27282,21 @@ mod tests {
       ".foo { filter: contrast(175%) brightness(3%); }",
       ".foo{filter:contrast(175%)brightness(3%)}",
     );
-    minify_test(".foo { filter: hue-rotate(0) }", ".foo{filter:hue-rotate()}");
+    minify_test(".foo { filter: hue-rotate(0) }", ".foo{filter:hue-rotate(0)}");
+
+    prefix_test(
+      ".foo { filter: brightness(1) }",
+      indoc! { r#"
+        .foo {
+          -webkit-filter: brightness(1);
+          filter: brightness(1);
+        }
+      "#},
+      Browsers {
+        chrome: Some(20 << 16),
+        ..Browsers::default()
+      },
+    );
 
     prefix_test(
       ".foo { filter: blur(5px) }",
diff --git a/src/properties/effects.rs b/src/properties/effects.rs
index 1ba69f6a..04b7c06b 100644
--- a/src/properties/effects.rs
+++ b/src/properties/effects.rs
@@ -122,72 +122,47 @@ impl<'i> ToCss for Filter<'i> {
     match self {
       Filter::Blur(val) => {
         dest.write_str("blur(")?;
-        if *val != Length::zero() {
-          val.to_css(dest)?;
-        }
+        val.to_css(dest)?;
         dest.write_char(')')
       }
       Filter::Brightness(val) => {
         dest.write_str("brightness(")?;
-        let v: f32 = val.into();
-        if v != 1.0 {
-          val.to_css(dest)?;
-        }
+        val.to_css(dest)?;
         dest.write_char(')')
       }
       Filter::Contrast(val) => {
         dest.write_str("contrast(")?;
-        let v: f32 = val.into();
-        if v != 1.0 {
-          val.to_css(dest)?;
-        }
+        val.to_css(dest)?;
         dest.write_char(')')
       }
       Filter::Grayscale(val) => {
         dest.write_str("grayscale(")?;
-        let v: f32 = val.into();
-        if v != 1.0 {
-          val.to_css(dest)?;
-        }
+        val.to_css(dest)?;
         dest.write_char(')')
       }
       Filter::HueRotate(val) => {
         dest.write_str("hue-rotate(")?;
-        if !val.is_zero() {
-          val.to_css(dest)?;
-        }
+        val.to_css_with_unitless_zero(dest)?;
         dest.write_char(')')
       }
       Filter::Invert(val) => {
         dest.write_str("invert(")?;
-        let v: f32 = val.into();
-        if v != 1.0 {
-          val.to_css(dest)?;
-        }
+        val.to_css(dest)?;
         dest.write_char(')')
       }
       Filter::Opacity(val) => {
         dest.write_str("opacity(")?;
-        let v: f32 = val.into();
-        if v != 1.0 {
-          val.to_css(dest)?;
-        }
+        val.to_css(dest)?;
         dest.write_char(')')
       }
       Filter::Saturate(val) => {
         dest.write_str("saturate(")?;
-        let v: f32 = val.into();
-        if v != 1.0 {
-          val.to_css(dest)?;
-        }
+        val.to_css(dest)?;
         dest.write_char(')')
       }
       Filter::Sepia(val) => {
         dest.write_str("sepia(")?;
-        let v: f32 = val.into();
-        if v != 1.0 {
-          val.to_css(dest)?;
-        }
+        val.to_css(dest)?;
         dest.write_char(')')
       }
       Filter::DropShadow(val) => {