diff --git a/lib/std/fmt.zig b/lib/std/fmt.zig
index 6141b18b5b67b9921a0cb52d27e2873c26bab7c8..6dbef5db67fe902f317298223e419e0320fc52de 100644
--- a/lib/std/fmt.zig
+++ b/lib/std/fmt.zig
@@ -578,7 +578,7 @@ fn formatFloatValue(
         @compileError("Unknown format string: '" ++ fmt ++ "'");
     }
 
-    return formatBuf(buf[0..buf_stream.pos], options, writer);
+    return formatBuf(buf_stream.getWritten(), options, writer);
 }
 
 pub fn formatText(