diff --git a/tests/files/raw_api.png b/tests/files/raw_api.png
new file mode 100644
index 00000000..3f9bdb1a
Binary files /dev/null and b/tests/files/raw_api.png differ
diff --git a/tests/raw.rs b/tests/raw.rs
new file mode 100644
index 00000000..997837a4
--- /dev/null
+++ b/tests/raw.rs
@@ -0,0 +1,97 @@
+use oxipng::internal_tests::*;
+use oxipng::*;
+use std::path::PathBuf;
+use std::sync::Arc;
+
+fn get_opts() -> Options {
+    Options {
+        force: true,
+        filter: indexset! { RowFilter::None },
+        ..Default::default()
+    }
+}
+
+fn test_it_converts(input: &str) {
+    let input = PathBuf::from(input);
+    let opts = get_opts();
+
+    let original_data = PngData::read_file(&PathBuf::from(input)).unwrap();
+    let png = PngData::from_slice(&original_data, opts.fix_errors).unwrap();
+    let png = Arc::try_unwrap(png.raw).unwrap();
+
+    let num_headers = png.aux_headers.len();
+    assert!(num_headers > 0);
+
+    let mut raw = RawImage::new(
+        png.ihdr.width,
+        png.ihdr.height,
+        png.ihdr.color_type,
+        png.ihdr.bit_depth,
+        png.data,
+    )
+    .unwrap();
+
+    for (chunk_type, data) in png.aux_headers {
+        raw.add_png_header(chunk_type, data);
+    }
+
+    let output = raw.create_optimized_png(&opts).unwrap();
+
+    let new = PngData::from_slice(&output, opts.fix_errors).unwrap();
+    assert!(new.raw.aux_headers.len() == num_headers);
+
+    #[cfg(feature = "sanity-checks")]
+    assert!(validate_output(&output, &original_data));
+}
+
+#[test]
+fn from_file() {
+    test_it_converts("tests/files/raw_api.png");
+}
+
+#[test]
+fn custom_indexed() {
+    let opts = get_opts();
+
+    let raw = RawImage::new(
+        4,
+        4,
+        ColorType::Indexed {
+            palette: vec![
+                RGBA8::new(255, 255, 255, 255),
+                RGBA8::new(255, 0, 0, 255),
+                RGBA8::new(0, 255, 0, 255),
+                RGBA8::new(0, 0, 255, 255),
+            ],
+        },
+        BitDepth::Eight,
+        vec![0, 0, 1, 1, 0, 0, 1, 1, 2, 2, 3, 3, 2, 2, 3, 3],
+    )
+    .unwrap();
+
+    raw.create_optimized_png(&opts).unwrap();
+}
+
+#[test]
+fn invalid_depth() {
+    RawImage::new(
+        2,
+        2,
+        ColorType::RGBA,
+        BitDepth::Four,
+        vec![0, 0, 1, 1, 0, 0, 1, 1, 2, 2, 3, 3, 2, 2, 3, 3],
+    )
+    .expect_err("Expected invalid depth for color type");
+}
+
+#[test]
+fn incorrect_length() {
+    RawImage::new(
+        2,
+        2,
+        ColorType::RGBA,
+        BitDepth::Eight,
+        vec![0, 0, 1, 1, 0, 0, 1, 1],
+    )
+    .expect_err("Expected incorrect data length");
+}