diff --git a/src/ImageSharp/Common/Helpers/Guard.cs b/src/ImageSharp/Common/Helpers/Guard.cs
index 603cf566f5..9258beb368 100644
--- a/src/ImageSharp/Common/Helpers/Guard.cs
+++ b/src/ImageSharp/Common/Helpers/Guard.cs
@@ -4,7 +4,6 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
-using System.Linq;
 
 namespace SixLabors.ImageSharp
 {
@@ -19,17 +18,11 @@ namespace SixLabors.ImageSharp
         /// </summary>
         /// <param name="value">The target object, which cannot be null.</param>
         /// <param name="parameterName">The name of the parameter that is to be checked.</param>
-        /// <param name="message">The error message, if any to add to the exception.</param>
         /// <exception cref="ArgumentNullException"><paramref name="value"/> is null</exception>
-        public static void NotNull(object value, string parameterName, string message = "")
+        public static void NotNull(object value, string parameterName)
         {
             if (value == null)
             {
-                if (!string.IsNullOrWhiteSpace(message))
-                {
-                    throw new ArgumentNullException(parameterName, message);
-                }
-
                 throw new ArgumentNullException(parameterName);
             }
         }
@@ -60,17 +53,16 @@ namespace SixLabors.ImageSharp
         /// <typeparam name="T">The type of objects in the <paramref name="value"/></typeparam>
         /// <param name="value">The target enumeration, which should be checked against being null or empty.</param>
         /// <param name="parameterName">Name of the parameter.</param>
-        /// <param name="message">The error message, if any to add to the exception.</param>
         /// <exception cref="ArgumentNullException"><paramref name="value"/> is null.</exception>
         /// <exception cref="ArgumentException"><paramref name="value"/> is empty.</exception>
-        public static void NotNullOrEmpty<T>(IEnumerable<T> value, string parameterName)
+        public static void NotNullOrEmpty<T>(ICollection<T> value, string parameterName)
         {
             if (value == null)
             {
                 throw new ArgumentNullException(parameterName);
             }
 
-            if (!value.Any())
+            if (value.Count == 0)
             {
                 throw new ArgumentException("Must not be empty.", parameterName);
             }
@@ -182,15 +174,9 @@ namespace SixLabors.ImageSharp
         /// Verifies, that the method parameter with specified target value is true
         /// and throws an exception if it is found to be so.
         /// </summary>
-        /// <param name="target">
-        /// The target value, which cannot be false.
-        /// </param>
-        /// <param name="parameterName">
-        /// The name of the parameter that is to be checked.
-        /// </param>
-        /// <param name="message">
-        /// The error message, if any to add to the exception.
-        /// </param>
+        /// <param name="target">The target value, which cannot be false.</param>
+        /// <param name="parameterName">The name of the parameter that is to be checked.</param>
+        /// <param name="message">The error message, if any to add to the exception.</param>
         /// <exception cref="ArgumentException">
         /// <paramref name="target"/> is false
         /// </exception>
diff --git a/src/ImageSharp/ImageExtensions.cs b/src/ImageSharp/ImageExtensions.cs
index 2cdb71fc0e..75d947469b 100644
--- a/src/ImageSharp/ImageExtensions.cs
+++ b/src/ImageSharp/ImageExtensions.cs
@@ -30,7 +30,7 @@ namespace SixLabors.ImageSharp
         public static void Save<TPixel>(this Image<TPixel> source, string filePath)
             where TPixel : struct, IPixel<TPixel>
         {
-            Guard.NotNullOrEmpty(filePath, nameof(filePath));
+            Guard.NotNullOrWhiteSpace(filePath, nameof(filePath));
 
             string ext = Path.GetExtension(filePath).Trim('.');
             IImageFormat format = source.GetConfiguration().ImageFormatsManager.FindFormatByFileExtension(ext);
diff --git a/tests/ImageSharp.Tests/Helpers/GuardTests.cs b/tests/ImageSharp.Tests/Helpers/GuardTests.cs
index 83075dc83e..42913e02d4 100644
--- a/tests/ImageSharp.Tests/Helpers/GuardTests.cs
+++ b/tests/ImageSharp.Tests/Helpers/GuardTests.cs
@@ -35,27 +35,27 @@ namespace SixLabors.ImageSharp.Tests.Helpers
         /// </summary>
         [Fact]
         [SuppressMessage("StyleCop.CSharp.ReadabilityRules", "SA1122:UseStringEmptyForEmptyStrings", Justification = "Reviewed. Suppression is OK here.")]
-        public void NotEmptyThrowsWhenEmpty()
+        public void NotEmptyOrWhiteSpaceThrowsWhenEmpty()
         {
-            Assert.Throws<ArgumentException>(() => Guard.NotNullOrEmpty("", string.Empty));
+            Assert.Throws<ArgumentException>(() => Guard.NotNullOrWhiteSpace("", string.Empty));
         }
 
         /// <summary>
         /// Tests that the <see cref="M:Guard.NotEmpty"/> method throws when the argument is whitespace.
         /// </summary>
         [Fact]
-        public void NotEmptyThrowsWhenWhitespace()
+        public void NotEmptyOrWhiteSpaceThrowsOnWhitespace()
         {
-            Assert.Throws<ArgumentException>(() => Guard.NotNullOrEmpty(" ", string.Empty));
+            Assert.Throws<ArgumentException>(() => Guard.NotNullOrWhiteSpace(" ", string.Empty));
         }
 
         /// <summary>
         /// Tests that the <see cref="M:Guard.NotEmpty"/> method throws when the argument name is null.
         /// </summary>
         [Fact]
-        public void NotEmptyThrowsWhenParameterNameNull()
+        public void NotEmptyOrWhiteSpaceThrowsWhenParameterNameNull()
         {
-            Assert.Throws<ArgumentNullException>(() => Guard.NotNullOrEmpty(null, null));
+            Assert.Throws<ArgumentNullException>(() => Guard.NotNullOrWhiteSpace(null, null));
         }
 
         /// <summary>