diff --git a/source/dotnet/Library/AdaptiveCards.Rendering.Html/AdaptiveCardRenderer.cs b/source/dotnet/Library/AdaptiveCards.Rendering.Html/AdaptiveCardRenderer.cs
index fb65de4b02..4fe769ccd6 100644
--- a/source/dotnet/Library/AdaptiveCards.Rendering.Html/AdaptiveCardRenderer.cs
+++ b/source/dotnet/Library/AdaptiveCards.Rendering.Html/AdaptiveCardRenderer.cs
@@ -944,7 +944,7 @@ protected static HtmlTag TextBlockRender(AdaptiveTextBlock textBlock, AdaptiveRe
                 .Style("box-sizing", "border-box")
                 .Style("text-align", textBlock.HorizontalAlignment.ToString().ToLower())
                 .Style("color", context.GetColor(textBlock.Color, textBlock.IsSubtle, false))
-                .Style("line-height", $"{lineHeight.ToString("F")}px")
+                .Style("line-height", $"{lineHeight.ToString("F", System.Globalization.CultureInfo.InvariantCulture)}px")
                 .Style("font-size", $"{fontSize}px")
                 .Style("font-weight", $"{weight}");
 
@@ -1065,7 +1065,7 @@ protected static HtmlTag TextRunRender(AdaptiveTextRun textRun, AdaptiveRenderCo
             var uiTextRun = new HtmlTag("span", true)
                 .AddClass($"ac-{textRun.Type.Replace(".", "").ToLower()}")
                 .Style("color", context.GetColor(textRun.Color, textRun.IsSubtle, false))
-                .Style("line-height", $"{lineHeight.ToString("F")}px")
+                .Style("line-height", $"{lineHeight.ToString("F", System.Globalization.CultureInfo.InvariantCulture)}px")
                 .Style("font-size", $"{fontSize}px")
                 .Style("font-weight", $"{weight}");
 
diff --git a/source/dotnet/Library/AdaptiveCards.Rendering.Html/AdaptiveRenderContext.cs b/source/dotnet/Library/AdaptiveCards.Rendering.Html/AdaptiveRenderContext.cs
index 1ebbce0b50..23c6aa82eb 100644
--- a/source/dotnet/Library/AdaptiveCards.Rendering.Html/AdaptiveRenderContext.cs
+++ b/source/dotnet/Library/AdaptiveCards.Rendering.Html/AdaptiveRenderContext.cs
@@ -144,7 +144,7 @@ public string GetRGBColor(string color)
                 if (color.Length == 9)
                 {
                     var opacity = (float)Convert.ToByte(color.Substring(1, 2), 16) / Byte.MaxValue;
-                    return $"rgba({Convert.ToByte(color.Substring(3, 2), 16)}, {Convert.ToByte(color.Substring(5, 2), 16)}, {Convert.ToByte(color.Substring(7, 2), 16)}, {opacity.ToString("F")})";
+                    return $"rgba({Convert.ToByte(color.Substring(3, 2), 16)}, {Convert.ToByte(color.Substring(5, 2), 16)}, {Convert.ToByte(color.Substring(7, 2), 16)}, {opacity.ToString("F", System.Globalization.CultureInfo.InvariantCulture)})";
                 }
             }
             return color;