diff --git a/src/ImageSharp/Formats/Png/PngThrowHelper.cs b/src/ImageSharp/Formats/Png/PngThrowHelper.cs
index ad733f0105..ae7d16ec71 100644
--- a/src/ImageSharp/Formats/Png/PngThrowHelper.cs
+++ b/src/ImageSharp/Formats/Png/PngThrowHelper.cs
@@ -22,7 +22,7 @@ namespace SixLabors.ImageSharp.Formats.Png
         public static void ThrowNoData() => throw new InvalidImageContentException("PNG Image does not contain a data chunk");
 
         [MethodImpl(InliningOptions.ColdPath)]
-        public static void ThrowMissingPalette() => throw new InvalidImageContentException("PNG Image does not contain palette chunk");
+        public static void ThrowMissingPalette() => throw new InvalidImageContentException("PNG Image does not contain a palette chunk");
 
         [MethodImpl(InliningOptions.ColdPath)]
         public static void ThrowInvalidChunkType() => throw new InvalidImageContentException("Invalid PNG data.");
diff --git a/tests/ImageSharp.Tests/Formats/Png/PngDecoderTests.cs b/tests/ImageSharp.Tests/Formats/Png/PngDecoderTests.cs
index f81a77ca12..a92856c730 100644
--- a/tests/ImageSharp.Tests/Formats/Png/PngDecoderTests.cs
+++ b/tests/ImageSharp.Tests/Formats/Png/PngDecoderTests.cs
@@ -278,7 +278,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Png
                     image.DebugSave(provider);
                 });
             Assert.NotNull(ex);
-            Assert.Contains("PNG Image does not contain palette chunk", ex.Message);
+            Assert.Contains("PNG Image does not contain a palette chunk", ex.Message);
         }
 
         [Theory]