diff --git a/src/Markdig/Extensions/Alerts/AlertBlock.cs b/src/Markdig/Extensions/Alerts/AlertBlock.cs
index f8bb7431..4e5ff529 100644
--- a/src/Markdig/Extensions/Alerts/AlertBlock.cs
+++ b/src/Markdig/Extensions/Alerts/AlertBlock.cs
@@ -16,7 +16,7 @@ public class AlertBlock : QuoteBlock
/// Creates a new instance of this block.
///
///
- public AlertBlock(StringSlice kind) : base(null!)
+ public AlertBlock(StringSlice kind) : base(null)
{
Kind = kind;
}
diff --git a/src/Markdig/Syntax/QuoteBlock.cs b/src/Markdig/Syntax/QuoteBlock.cs
index 30379aae..251e4273 100644
--- a/src/Markdig/Syntax/QuoteBlock.cs
+++ b/src/Markdig/Syntax/QuoteBlock.cs
@@ -19,7 +19,7 @@ public class QuoteBlock : ContainerBlock
/// Initializes a new instance of the class.
///
/// The parser used to create this block.
- public QuoteBlock(BlockParser parser) : base(parser)
+ public QuoteBlock(BlockParser? parser) : base(parser)
{
}