diff --git a/benches/reductions.rs b/benches/reductions.rs
index e94d8280..30eebe17 100644
--- a/benches/reductions.rs
+++ b/benches/reductions.rs
@@ -80,7 +80,7 @@ fn reductions_rgba_to_rgb_16(b: &mut Bencher) {
     let input = test::black_box(PathBuf::from("tests/files/rgba_16_should_be_rgb_16.png"));
     let png = PngData::new(&input, false).unwrap();
 
-    b.iter(|| reduce_color_type(&png.raw));
+    b.iter(|| reduce_color_type(&png.raw, true));
 }
 
 #[bench]
@@ -88,7 +88,7 @@ fn reductions_rgba_to_rgb_8(b: &mut Bencher) {
     let input = test::black_box(PathBuf::from("tests/files/rgba_8_should_be_rgb_8.png"));
     let png = PngData::new(&input, false).unwrap();
 
-    b.iter(|| reduce_color_type(&png.raw));
+    b.iter(|| reduce_color_type(&png.raw, true));
 }
 
 #[bench]
@@ -98,7 +98,7 @@ fn reductions_rgba_to_grayscale_alpha_16(b: &mut Bencher) {
     ));
     let png = PngData::new(&input, false).unwrap();
 
-    b.iter(|| reduce_color_type(&png.raw));
+    b.iter(|| reduce_color_type(&png.raw, true));
 }
 
 #[bench]
@@ -108,7 +108,7 @@ fn reductions_rgba_to_grayscale_alpha_8(b: &mut Bencher) {
     ));
     let png = PngData::new(&input, false).unwrap();
 
-    b.iter(|| reduce_color_type(&png.raw));
+    b.iter(|| reduce_color_type(&png.raw, true));
 }
 
 #[bench]
@@ -118,7 +118,7 @@ fn reductions_rgba_to_grayscale_16(b: &mut Bencher) {
     ));
     let png = PngData::new(&input, false).unwrap();
 
-    b.iter(|| reduce_color_type(&png.raw));
+    b.iter(|| reduce_color_type(&png.raw, true));
 }
 
 #[bench]
@@ -128,7 +128,7 @@ fn reductions_rgba_to_grayscale_8(b: &mut Bencher) {
     ));
     let png = PngData::new(&input, false).unwrap();
 
-    b.iter(|| reduce_color_type(&png.raw));
+    b.iter(|| reduce_color_type(&png.raw, true));
 }
 
 #[bench]
@@ -138,7 +138,7 @@ fn reductions_rgb_to_grayscale_16(b: &mut Bencher) {
     ));
     let png = PngData::new(&input, false).unwrap();
 
-    b.iter(|| reduce_color_type(&png.raw));
+    b.iter(|| reduce_color_type(&png.raw, true));
 }
 
 #[bench]
@@ -146,7 +146,7 @@ fn reductions_rgb_to_grayscale_8(b: &mut Bencher) {
     let input = test::black_box(PathBuf::from("tests/files/rgb_8_should_be_grayscale_8.png"));
     let png = PngData::new(&input, false).unwrap();
 
-    b.iter(|| reduce_color_type(&png.raw));
+    b.iter(|| reduce_color_type(&png.raw, true));
 }
 
 #[bench]
@@ -154,7 +154,7 @@ fn reductions_rgba_to_palette_8(b: &mut Bencher) {
     let input = test::black_box(PathBuf::from("tests/files/rgba_8_should_be_palette_8.png"));
     let png = PngData::new(&input, false).unwrap();
 
-    b.iter(|| reduce_color_type(&png.raw));
+    b.iter(|| reduce_color_type(&png.raw, true));
 }
 
 #[bench]
@@ -162,7 +162,7 @@ fn reductions_rgb_to_palette_8(b: &mut Bencher) {
     let input = test::black_box(PathBuf::from("tests/files/rgb_8_should_be_palette_8.png"));
     let png = PngData::new(&input, false).unwrap();
 
-    b.iter(|| reduce_color_type(&png.raw));
+    b.iter(|| reduce_color_type(&png.raw, true));
 }
 
 #[bench]
diff --git a/src/lib.rs b/src/lib.rs
index 0b6fc479..239968de 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -169,6 +169,10 @@ pub struct Options {
     ///
     /// Default: `true`
     pub palette_reduction: bool,
+    /// Whether to attempt grayscale reduction
+    ///
+    /// Default: `true`
+    pub grayscale_reduction: bool,
     /// Whether to perform IDAT recoding
     ///
     /// If any type of reduction is performed, IDAT recoding will be performed
@@ -305,6 +309,7 @@ impl Default for Options {
             bit_depth_reduction: true,
             color_type_reduction: true,
             palette_reduction: true,
+            grayscale_reduction: true,
             idat_recoding: true,
             strip: Headers::None,
             deflate: Deflaters::Zlib {
@@ -741,7 +746,7 @@ fn perform_reductions(
     }
 
     if opts.color_type_reduction {
-        if let Some(reduced) = reduce_color_type(&png) {
+        if let Some(reduced) = reduce_color_type(&png, opts.grayscale_reduction) {
             png = Arc::new(reduced);
             eval.try_image(png.clone());
             report_reduction(&png);
diff --git a/src/main.rs b/src/main.rs
index 20c8f16b..1a269dd4 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -184,6 +184,9 @@ fn main() {
         .arg(Arg::with_name("no-palette-reduction")
             .help("No palette reduction")
             .long("np"))
+        .arg(Arg::with_name("no-grayscale-reduction")
+            .help("No grayscale reduction")
+            .long("ng"))
         .arg(Arg::with_name("no-reductions")
             .help("No reductions")
             .long("nx"))
@@ -433,10 +436,15 @@ fn parse_opts_into_struct(
         opts.palette_reduction = false;
     }
 
+    if matches.is_present("no-grayscale-reduction") {
+        opts.grayscale_reduction = false;
+    }
+
     if matches.is_present("no-reductions") {
         opts.bit_depth_reduction = false;
         opts.color_type_reduction = false;
         opts.palette_reduction = false;
+        opts.grayscale_reduction = false;
     }
 
     if matches.is_present("no-recoding") {
diff --git a/src/reduction/mod.rs b/src/reduction/mod.rs
index e6f4bf7d..6b89b839 100644
--- a/src/reduction/mod.rs
+++ b/src/reduction/mod.rs
@@ -185,15 +185,19 @@ fn reordered_palette(palette: &[RGBA8], palette_map: &[Option<u8>; 256]) -> Vec<
 
 /// Attempt to reduce the color type of the image
 /// Returns true if the color type was reduced, false otherwise
-pub fn reduce_color_type(png: &PngImage) -> Option<PngImage> {
+pub fn reduce_color_type(png: &PngImage, grayscale_reduction: bool) -> Option<PngImage> {
     let mut should_reduce_bit_depth = false;
     let mut reduced = Cow::Borrowed(png);
 
     // Go down one step at a time
     // Maybe not the most efficient, but it's safe
     if reduced.ihdr.color_type == ColorType::RGBA {
-        if let Some(r) =
-            reduce_rgba_to_grayscale_alpha(&reduced).or_else(|| reduced_alpha_channel(&reduced))
+        if let Some(r) = if grayscale_reduction {
+            reduce_rgba_to_grayscale_alpha(&reduced)
+        } else {
+            None
+        }
+        .or_else(|| reduced_alpha_channel(&reduced))
         {
             reduced = Cow::Owned(r);
         } else if let Some(r) = reduced_color_to_palette(&reduced) {
@@ -210,8 +214,12 @@ pub fn reduce_color_type(png: &PngImage) -> Option<PngImage> {
     }
 
     if reduced.ihdr.color_type == ColorType::RGB {
-        if let Some(r) =
-            reduce_rgb_to_grayscale(&reduced).or_else(|| reduced_color_to_palette(&reduced))
+        if let Some(r) = if grayscale_reduction {
+            reduce_rgb_to_grayscale(&reduced)
+        } else {
+            None
+        }
+        .or_else(|| reduced_color_to_palette(&reduced))
         {
             reduced = Cow::Owned(r);
             should_reduce_bit_depth = true;