diff --git a/src/Umbraco.Core/Templates/HtmlImageSourceParser.cs b/src/Umbraco.Core/Templates/HtmlImageSourceParser.cs
index a8a5781288f9..f79d29023b32 100644
--- a/src/Umbraco.Core/Templates/HtmlImageSourceParser.cs
+++ b/src/Umbraco.Core/Templates/HtmlImageSourceParser.cs
@@ -136,7 +136,11 @@ public string EnsureImageSources(string text)
 
             // Re-sign the URL so a rotated HMAC secret key doesn't break previously-authored images.
             // No-op when HMAC isn't configured.
-            var refreshedSrc = _imageUrlTokenGenerator.RefreshSignature($"{mediaUrl}{src.Groups[2].Value}");
+            var queryString = src.Groups[2].Value;
+            var composedUrl = queryString.IsNullOrWhiteSpace()
+                ? mediaUrl
+                : mediaUrl.AppendQueryStringToUrl(queryString);
+            var refreshedSrc = _imageUrlTokenGenerator.RefreshSignature(composedUrl);
 
             return match.Value.Replace(src.Value, $"src=\"{refreshedSrc}\"");
         });
diff --git a/src/Umbraco.Infrastructure/DeliveryApi/ApiRichTextMarkupParser.cs b/src/Umbraco.Infrastructure/DeliveryApi/ApiRichTextMarkupParser.cs
index 75de44914c11..85a5f8d24948 100644
--- a/src/Umbraco.Infrastructure/DeliveryApi/ApiRichTextMarkupParser.cs
+++ b/src/Umbraco.Infrastructure/DeliveryApi/ApiRichTextMarkupParser.cs
@@ -126,7 +126,10 @@ private void ReplaceLocalImages(HtmlDocument doc, IPublishedMediaCache mediaCach
 
                 // Re-sign the URL so a rotated HMAC secret key doesn't break previously-authored images.
                 // No-op when HMAC isn't configured.
-                var refreshedSrc = _imageUrlTokenGenerator.RefreshSignature($"{mediaUrl}{currentImageQueryString}");
+                var refreshedSrc = _imageUrlTokenGenerator.RefreshSignature(
+                    currentImageQueryString.IsNullOrWhiteSpace()
+                        ? mediaUrl
+                        : mediaUrl.AppendQueryStringToUrl(currentImageQueryString));
                 image.SetAttributeValue("src", refreshedSrc);
                 image.Attributes.Remove("data-udi");
 
diff --git a/tests/Umbraco.Tests.UnitTests/Umbraco.Core/Templates/HtmlImageSourceParserTests.cs b/tests/Umbraco.Tests.UnitTests/Umbraco.Core/Templates/HtmlImageSourceParserTests.cs
index 2fc1e1d1f777..033753a1e19e 100644
--- a/tests/Umbraco.Tests.UnitTests/Umbraco.Core/Templates/HtmlImageSourceParserTests.cs
+++ b/tests/Umbraco.Tests.UnitTests/Umbraco.Core/Templates/HtmlImageSourceParserTests.cs
@@ -264,4 +264,46 @@ public void EnsureImageSources_Noop_Signer_Leaves_Src_Unchanged()
             @"<img src=""/media/1001/image.jpg?width=100"" data-udi=""umb://media/81BB2036034F418BB61FC7160D68DCD4""/>",
             result);
     }
+
+    [Test]
+    public void Ensure_ImageSources_Processing_With_Cache_Buster()
+    {
+        var sourceHtml = """<div><img data-udi="umb://media/81BB2036034F418BB61FC7160D68DCD4" src="?width=100&height=500" /></div>""";
+        var fakeMediaUrl = "/media/1001/image.jpg?rand=1234";
+
+        var parser = new HtmlImageSourceParser(guid => fakeMediaUrl, NoopSigner());
+        var actual = parser.EnsureImageSources(sourceHtml);
+
+        Assert.AreEqual(
+            """<div><img data-udi="umb://media/81BB2036034F418BB61FC7160D68DCD4" src="/media/1001/image.jpg?rand=1234&width=100&height=500" /></div>""",
+            actual);
+    }
+
+    [Test]
+    public void Ensure_ImageSources_With_Cache_Buster_And_No_Query_String()
+    {
+        var sourceHtml = """<div><img data-udi="umb://media/81BB2036034F418BB61FC7160D68DCD4" src="" /></div>""";
+        var fakeMediaUrl = "/media/1001/image.jpg?rand=1234";
+
+        var parser = new HtmlImageSourceParser(guid => fakeMediaUrl, NoopSigner());
+        var actual = parser.EnsureImageSources(sourceHtml);
+
+        Assert.AreEqual(
+            """<div><img data-udi="umb://media/81BB2036034F418BB61FC7160D68DCD4" src="/media/1001/image.jpg?rand=1234" /></div>""",
+            actual);
+    }
+
+    [Test]
+    public void Ensure_ImageSources_With_No_Query_String_Does_Not_Append_Trailing_Query()
+    {
+        var sourceHtml = """<div><img data-udi="umb://media/81BB2036034F418BB61FC7160D68DCD4" src="" /></div>""";
+        var fakeMediaUrl = "/media/1001/image.jpg";
+
+        var parser = new HtmlImageSourceParser(guid => fakeMediaUrl, NoopSigner());
+        var actual = parser.EnsureImageSources(sourceHtml);
+
+        Assert.AreEqual(
+            """<div><img data-udi="umb://media/81BB2036034F418BB61FC7160D68DCD4" src="/media/1001/image.jpg" /></div>""",
+            actual);
+    }
 }
diff --git a/tests/Umbraco.Tests.UnitTests/Umbraco.Infrastructure/DeliveryApi/ApiRichTextMarkupParserTests.cs b/tests/Umbraco.Tests.UnitTests/Umbraco.Infrastructure/DeliveryApi/ApiRichTextMarkupParserTests.cs
index 4ae164428dfd..5c69132a8243 100644
--- a/tests/Umbraco.Tests.UnitTests/Umbraco.Infrastructure/DeliveryApi/ApiRichTextMarkupParserTests.cs
+++ b/tests/Umbraco.Tests.UnitTests/Umbraco.Infrastructure/DeliveryApi/ApiRichTextMarkupParserTests.cs
@@ -180,6 +180,31 @@ public void Can_Parse_Inline_LocalImages()
         Assert.AreEqual(expectedOutput, parsedHtml);
     }
 
+    [Test]
+    public void Can_Parse_Inline_LocalImages_With_Cache_Buster()
+    {
+        var key1 = Guid.Parse("395bdc0e8f4d4ad4af7f3a3f6265651e");
+        var data1 = new MockData()
+            .WithKey(key1)
+            .WithMediaUrl("https://localhost:44331/media/bdofwokn/77gtp8fbrxmgkefatp10aw.webp?rand=1234");
+
+        var mockData = new Dictionary<Guid, MockData>
+        {
+            { key1, data1 },
+        };
+        var parser = BuildDefaultSut(mockData);
+
+        var markup =
+            @"<p>An image</p>\n<p><img src=""?rmode=max&amp;width=500&amp;height=500"" alt="""" width=""500"" height=""500"" data-udi=""umb://media/395bdc0e8f4d4ad4af7f3a3f6265651e""></p>";
+
+        var expectedOutput =
+            @"<p>An image</p>\n<p><img src=""https://localhost:44331/media/bdofwokn/77gtp8fbrxmgkefatp10aw.webp?rand=1234&rmode=max&amp;width=500&amp;height=500"" alt="""" width=""500"" height=""500""></p>";
+
+        var parsedHtml = parser.Parse(markup);
+
+        Assert.AreEqual(expectedOutput, parsedHtml);
+    }
+
     [Test]
     public void LocalImages_Are_ReSigned_Via_TokenGenerator()
     {