diff --git a/src/ops.c b/src/ops.c
index 856133c..090d3f8 100644
--- a/src/ops.c
+++ b/src/ops.c
@@ -6642,6 +6642,14 @@
 	}
     }
 
+    /* Without any lines make the register empty. */
+    if (y_ptr->y_size + newlines == 0)
+    {
+	vim_free(y_ptr->y_array);
+	y_ptr->y_array = NULL;
+	return;
+    }
+
     /*
      * Allocate an array to hold the pointers to the new register lines.
      * If the register was not empty, move the existing lines to the new array.
diff --git a/src/version.c b/src/version.c
index ba5f30e..822da62 100644
--- a/src/version.c
+++ b/src/version.c
@@ -742,6 +742,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    725,
+/**/
     724,
 /**/
     723,