diff --git a/renderdocui/Code/FormatElement.cs b/renderdocui/Code/FormatElement.cs
index 33b59bcd8..65185ae14 100644
--- a/renderdocui/Code/FormatElement.cs
+++ b/renderdocui/Code/FormatElement.cs
@@ -325,7 +325,7 @@ namespace renderdocui.Code
             return ret;
         }
 
-        static public FormatElement[] ParseFormatString(string formatString, bool tightPacking, out string errors)
+        static public FormatElement[] ParseFormatString(string formatString, UInt64 maxLen, bool tightPacking, out string errors)
         {
             var elems = new List<FormatElement>();
 
@@ -586,6 +586,11 @@ namespace renderdocui.Code
 
                 var fmt = new ResourceFormat(FormatComponentType.UInt, 4, 4);
 
+                if (maxLen > 0 && maxLen < 16)
+                    fmt.compCount = 1;
+                if (maxLen > 0 && maxLen < 4)
+                    fmt.compByteWidth = 1;
+
                 elems.Add(new FormatElement("data", 0, 0, false, 1, false, 1, fmt, true));
             }
 
diff --git a/renderdocui/Windows/BufferViewer.cs b/renderdocui/Windows/BufferViewer.cs
index 0ebb6a7ee..caa79142d 100644
--- a/renderdocui/Windows/BufferViewer.cs
+++ b/renderdocui/Windows/BufferViewer.cs
@@ -677,12 +677,14 @@ namespace renderdocui.Windows
 
             m_FormatText = formatString;
 
+            UInt64 len = 0;
             Text = "Buffer Contents";
             foreach (var b in m_Core.CurBuffers)
             {
                 if (b.ID == id)
                 {
                     Text = b.name + " - Contents";
+                    len = b.byteSize;
                     break;
                 }
             }
@@ -691,7 +693,7 @@ namespace renderdocui.Windows
 
             string errors = "";
 
-            FormatElement[] elems = FormatElement.ParseFormatString(formatString, true, out errors);
+            FormatElement[] elems = FormatElement.ParseFormatString(formatString, len, true, out errors);
 
             input.Strides = new uint[] { elems.Last().offset + elems.Last().ByteSize };
             input.Buffers = new ResourceId[] { isBuffer ? id : ResourceId.Null, isBuffer ? ResourceId.Null : id };
diff --git a/renderdocui/Windows/Dialogs/ConstantBufferPreviewer.cs b/renderdocui/Windows/Dialogs/ConstantBufferPreviewer.cs
index 2aca4efcd..3040c01a8 100644
--- a/renderdocui/Windows/Dialogs/ConstantBufferPreviewer.cs
+++ b/renderdocui/Windows/Dialogs/ConstantBufferPreviewer.cs
@@ -406,7 +406,7 @@ namespace renderdocui.Controls
 			{
 				string errors = "";
 
-				m_FormatOverride = FormatElement.ParseFormatString(formatText, false, out errors);
+				m_FormatOverride = FormatElement.ParseFormatString(formatText, 0, false, out errors);
 
 				if (m_FormatSpecifier != null)
 					m_FormatSpecifier.SetErrors(errors);