diff --git a/src/Utf8StringInterpolation/Shims.cs b/src/Utf8StringInterpolation/Shims.cs
index d20b9f1..031104c 100644
--- a/src/Utf8StringInterpolation/Shims.cs
+++ b/src/Utf8StringInterpolation/Shims.cs
@@ -28,7 +28,7 @@ public static bool TryFormat(this char value, Span<byte> utf8Destination, out in
             }
 #endif
         }
-                
+
 #if !NET8_0_OR_GREATER
         public static bool TryFormat(this DateTime value, Span<byte> utf8Destination, out int bytesWritten, string? format, IFormatProvider? formatProvider)
         {
@@ -46,14 +46,15 @@ public static bool TryFormat(this DateTime value, Span<byte> utf8Destination, ou
                 }
             }
 
-            var count = Encoding.UTF8.GetByteCount(charDest.Slice(0, charWritten));
+            var slice = charDest.Slice(0, charWritten);
+            var count = Encoding.UTF8.GetByteCount(slice);
             if (utf8Destination.Length < count)
             {
                 bytesWritten = 0;
                 return false;
             }
 
-            bytesWritten = Encoding.UTF8.GetBytes(charDest.Slice(0, charWritten), utf8Destination);
+            bytesWritten = Encoding.UTF8.GetBytes(slice, utf8Destination);
             return true;
         }
 
@@ -73,14 +74,15 @@ public static bool TryFormat(this DateTimeOffset value, Span<byte> utf8Destinati
                 }
             }
 
-            var count = Encoding.UTF8.GetByteCount(charDest.Slice(0, charWritten));
+            var slice = charDest.Slice(0, charWritten);
+            var count = Encoding.UTF8.GetByteCount(slice);
             if (utf8Destination.Length < count)
             {
                 bytesWritten = 0;
                 return false;
             }
 
-            bytesWritten = Encoding.UTF8.GetBytes(charDest.Slice(0, charWritten), utf8Destination);
+            bytesWritten = Encoding.UTF8.GetBytes(slice, utf8Destination);
             return true;
         }
 
@@ -100,14 +102,15 @@ public static bool TryFormat(this TimeSpan value, Span<byte> utf8Destination, ou
                 }
             }
 
-            var count = Encoding.UTF8.GetByteCount(charDest.Slice(0, charWritten));
+            var slice = charDest.Slice(0, charWritten);
+            var count = Encoding.UTF8.GetByteCount(slice);
             if (utf8Destination.Length < count)
             {
                 bytesWritten = 0;
                 return false;
             }
 
-            bytesWritten = Encoding.UTF8.GetBytes(charDest.Slice(0, charWritten), utf8Destination);
+            bytesWritten = Encoding.UTF8.GetBytes(slice, utf8Destination);
             return true;
         }
 #endif
diff --git a/src/Utf8StringInterpolation/Utf8StringWriter.cs b/src/Utf8StringInterpolation/Utf8StringWriter.cs
index d3d8396..133cdf0 100644
--- a/src/Utf8StringInterpolation/Utf8StringWriter.cs
+++ b/src/Utf8StringInterpolation/Utf8StringWriter.cs
@@ -351,9 +351,10 @@ int AppendSpanFormattable<T>(T value, string? format)
             }
         }
 
-        var count = Encoding.UTF8.GetByteCount(charDest.Slice(0, charWritten));
+        var slice = charDest.Slice(0, charWritten);
+        var count = Encoding.UTF8.GetByteCount(slice);
         TryGrow(count);
-        var bytesWritten = Encoding.UTF8.GetBytes(charDest.Slice(0, charWritten), destination);
+        var bytesWritten = Encoding.UTF8.GetBytes(slice, destination);
         destination = destination.Slice(bytesWritten);
         currentWritten += bytesWritten;
         return bytesWritten;