diff --git a/src/xdisp.c b/src/xdisp.c
index aa75fcaf77..442b09b10b 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -20810,8 +20810,21 @@ maybe_produce_line_number (struct it *it)
   /* Compute the required width if needed.  */
   if (!it->lnum_width)
     {
-      if (NATNUMP (Vdisplay_line_number_width))
-	it->lnum_width = XFASTINT (Vdisplay_line_number_width);
+      if (display_line_numbers_grow_only && NATNUMP (Vdisplay_line_number_width))
+	{
+	  int min_lnum = XFASTINT (Vdisplay_line_number_width);
+	  ptrdiff_t max_lnum;
+
+	  max_lnum = this_line + it->w->desired_matrix->nrows - 1 - it->vpos;
+	  min_lnum = max (log10 (max_lnum) + 1, min_lnum);
+
+	  it->lnum_width = min_lnum;
+	  Vdisplay_line_number_width = make_number (min_lnum);
+	}
+      else if (NATNUMP (Vdisplay_line_number_width))
+	{
+	  it->lnum_width = XFASTINT (Vdisplay_line_number_width);
+	}
       else
 	{
 	  /* Max line number to be displayed cannot be more than
@@ -32495,6 +32508,14 @@ even if the actual number needs less space.
 The default value of nil means compute the space dynamically.
 Any other value is treated as nil.  */);
   Vdisplay_line_number_width = Qnil;
+  DEFSYM (Qdisplay_line_number_width, "display-line-number-width");
+  Fmake_variable_buffer_local (Qdisplay_line_number_width);
+
+  DEFVAR_BOOL ("display-line-numbers-grow-only", display_line_numbers_grow_only,
+	       doc: /* Non-nil means only dynamically grow the
+display, and never shrink. This variable is only taken into account
+when `display-line-number-width' is a positive number.*/);
+  display_line_numbers_grow_only = false;
 
   DEFVAR_BOOL ("inhibit-eval-during-redisplay", inhibit_eval_during_redisplay,
     doc: /* Non-nil means don't eval Lisp during redisplay.  */);