diff --git a/src/lsp/format.lsp b/src/lsp/format.lsp
index e5cc87663..a5f18c565 100644
--- a/src/lsp/format.lsp
+++ b/src/lsp/format.lsp
@@ -99,11 +99,11 @@
   (declare (type float x))
   (cond ((zerop x)
          ;; Zero is a special case which FLOAT-STRING cannot handle.
-         (if fdigits
+         (if (and fdigits (/= fdigits 0))
              (let ((s (make-string (1+ fdigits) :initial-element #\0)))
                (setf (schar s 0) #\.)
-               (values s (length s) t (zerop fdigits) 0))
-             (values "." 1 t t 0)))
+               (values s (length s) t nil 0))
+             (values ".0" 2 t nil 0)))
         (t
          (multiple-value-bind (e string)
              (cond