diff --git a/src/ImageSharp/Formats/Jpeg/PdfJsPort/Components/PdfJsFileMarker.cs b/src/ImageSharp/Formats/Jpeg/PdfJsPort/Components/PdfJsFileMarker.cs
index d6ff1e9ed..8e51c0b7c 100644
--- a/src/ImageSharp/Formats/Jpeg/PdfJsPort/Components/PdfJsFileMarker.cs
+++ b/src/ImageSharp/Formats/Jpeg/PdfJsPort/Components/PdfJsFileMarker.cs
@@ -6,7 +6,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components
     /// <summary>
     /// Represents a jpeg file marker
     /// </summary>
-    internal struct PdfJsFileMarker
+    internal readonly struct PdfJsFileMarker
     {
         /// <summary>
         /// Initializes a new instance of the <see cref="PdfJsFileMarker"/> struct.
@@ -34,9 +34,9 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components
         }
 
         /// <summary>
-        /// Gets or sets a value indicating whether the current marker is invalid
+        /// Gets a value indicating whether the current marker is invalid
         /// </summary>
-        public bool Invalid { get; set; }
+        public bool Invalid { get; }
 
         /// <summary>
         /// Gets the position of the marker within a stream
diff --git a/src/ImageSharp/Primitives/Rational.cs b/src/ImageSharp/Primitives/Rational.cs
index 6678eb954..fa3961ffa 100644
--- a/src/ImageSharp/Primitives/Rational.cs
+++ b/src/ImageSharp/Primitives/Rational.cs
@@ -12,7 +12,7 @@ namespace SixLabors.ImageSharp.Primitives
     /// <remarks>
     /// This is a very simplified implementation of a rational number designed for use with metadata only.
     /// </remarks>
-    public struct Rational : IEquatable<Rational>
+    public readonly struct Rational : IEquatable<Rational>
     {
         /// <summary>
         /// Initializes a new instance of the <see cref="Rational"/> struct.
@@ -41,7 +41,7 @@ namespace SixLabors.ImageSharp.Primitives
         /// <param name="simplify">Specified if the rational should be simplified.</param>
         public Rational(uint numerator, uint denominator, bool simplify)
         {
-            LongRational rational = new LongRational(numerator, denominator, simplify);
+            var rational = new LongRational(numerator, denominator, simplify);
 
             this.Numerator = (uint)rational.Numerator;
             this.Denominator = (uint)rational.Denominator;
@@ -63,7 +63,7 @@ namespace SixLabors.ImageSharp.Primitives
         /// <param name="bestPrecision">Whether to use the best possible precision when parsing the value.</param>
         public Rational(double value, bool bestPrecision)
         {
-            LongRational rational = new LongRational(Math.Abs(value), bestPrecision);
+            var rational = new LongRational(Math.Abs(value), bestPrecision);
 
             this.Numerator = (uint)rational.Numerator;
             this.Denominator = (uint)rational.Denominator;
@@ -129,19 +129,14 @@ namespace SixLabors.ImageSharp.Primitives
         /// <inheritdoc/>
         public override bool Equals(object obj)
         {
-            if (obj is Rational)
-            {
-                return this.Equals((Rational)obj);
-            }
-
-            return false;
+            return obj is Rational other && this.Equals(other);
         }
 
         /// <inheritdoc/>
         public bool Equals(Rational other)
         {
-            LongRational left = new LongRational(this.Numerator, this.Denominator);
-            LongRational right = new LongRational(other.Numerator, other.Denominator);
+            var left = new LongRational(this.Numerator, this.Denominator);
+            var right = new LongRational(other.Numerator, other.Denominator);
 
             return left.Equals(right);
         }
@@ -149,7 +144,7 @@ namespace SixLabors.ImageSharp.Primitives
         /// <inheritdoc/>
         public override int GetHashCode()
         {
-            LongRational self = new LongRational(this.Numerator, this.Denominator);
+            var self = new LongRational(this.Numerator, this.Denominator);
             return self.GetHashCode();
         }
 
@@ -180,7 +175,7 @@ namespace SixLabors.ImageSharp.Primitives
         /// <returns>The <see cref="string"/></returns>
         public string ToString(IFormatProvider provider)
         {
-            LongRational rational = new LongRational(this.Numerator, this.Denominator);
+            var rational = new LongRational(this.Numerator, this.Denominator);
             return rational.ToString(provider);
         }
     }
diff --git a/src/ImageSharp/Primitives/SignedRational.cs b/src/ImageSharp/Primitives/SignedRational.cs
index c2a7b3e23..955e9db5e 100644
--- a/src/ImageSharp/Primitives/SignedRational.cs
+++ b/src/ImageSharp/Primitives/SignedRational.cs
@@ -12,7 +12,7 @@ namespace SixLabors.ImageSharp.Primitives
     /// <remarks>
     /// This is a very simplified implementation of a rational number designed for use with metadata only.
     /// </remarks>
-    public struct SignedRational : IEquatable<SignedRational>
+    public readonly struct SignedRational : IEquatable<SignedRational>
     {
         /// <summary>
         /// Initializes a new instance of the <see cref="SignedRational"/> struct.
@@ -41,7 +41,7 @@ namespace SixLabors.ImageSharp.Primitives
         /// <param name="simplify">Specified if the rational should be simplified.</param>
         public SignedRational(int numerator, int denominator, bool simplify)
         {
-            LongRational rational = new LongRational(numerator, denominator, simplify);
+            var rational = new LongRational(numerator, denominator, simplify);
 
             this.Numerator = (int)rational.Numerator;
             this.Denominator = (int)rational.Denominator;
@@ -140,8 +140,8 @@ namespace SixLabors.ImageSharp.Primitives
         /// <inheritdoc/>
         public bool Equals(SignedRational other)
         {
-            LongRational left = new LongRational(this.Numerator, this.Denominator);
-            LongRational right = new LongRational(other.Numerator, other.Denominator);
+            var left = new LongRational(this.Numerator, this.Denominator);
+            var right = new LongRational(other.Numerator, other.Denominator);
 
             return left.Equals(right);
         }
@@ -180,7 +180,7 @@ namespace SixLabors.ImageSharp.Primitives
         /// <returns>The <see cref="string"/></returns>
         public string ToString(IFormatProvider provider)
         {
-            LongRational rational = new LongRational(this.Numerator, this.Denominator);
+            var rational = new LongRational(this.Numerator, this.Denominator);
             return rational.ToString(provider);
         }
     }