diff --git a/src/Interfaces/ICachedRegisterBlock.cs b/src/Interfaces/ICachedRegisterBlock.cs
index c259b39..e473329 100644
--- a/src/Interfaces/ICachedRegisterBlock.cs
+++ b/src/Interfaces/ICachedRegisterBlock.cs
@@ -42,6 +42,11 @@ public interface ICachedRegisterBlock : INotifyPropertyChanged
 		/// </summary>
 		bool HasChanges { get; }
 
+		/// <summary>
+		///   Gets the size of the cached block in bytes.
+		/// </summary>
+		int SizeInBytes { get; }
+
 		/// <summary>
 		///   Reads a section of the cache.
 		/// </summary>
diff --git a/src/PanelFactory.cs b/src/PanelFactory.cs
index 2cccfa4..1583868 100644
--- a/src/PanelFactory.cs
+++ b/src/PanelFactory.cs
@@ -143,6 +143,10 @@ private static double GetMaxPixelWidthOfNames(Value[] values)
 
 		private static void AddValueControl(StackPanel panel, double nameWidth, Value value, ICachedRegisterBlock block)
 		{
+			var end = value.Address + value.Length;
+			if (end > block.SizeInBytes)
+				throw new InvalidOperationException($"The panel value '{value.Name}' at {value.Address} (length {value.Length}) ends at {end}, which exceeds the register block size ({block.SizeInBytes} bytes). Increase the config block's size, or reduce the panel addresses.");
+
 			UserControl newControl;
 			switch (value.Type)
 			{