diff --git a/src/option.c b/src/option.c
index b9b59ee..ff7973f 100644
--- a/src/option.c
+++ b/src/option.c
@@ -4919,12 +4919,30 @@
 			    {
 				/* Remove flags that appear twice. */
 				for (s = newval; *s; ++s)
-				    if ((!(flags & P_COMMA) || *s != ',')
-					    && vim_strchr(s + 1, *s) != NULL)
+				{
+				    /* if options have P_FLAGLIST and
+				     * P_ONECOMMA such as 'whichwrap' */
+				    if (flags & P_ONECOMMA)
 				    {
-					STRMOVE(s, s + 1);
-					--s;
+					if (*s != ',' && *(s + 1) == ','
+					      && vim_strchr(s + 2, *s) != NULL)
+					{
+					    /* Remove the duplicated value and
+					     * the next comma. */
+					    STRMOVE(s, s + 2);
+					    s -= 2;
+					}
 				    }
+				    else
+				    {
+					if ((!(flags & P_COMMA) || *s != ',')
+					      && vim_strchr(s + 1, *s) != NULL)
+					{
+					    STRMOVE(s, s + 1);
+					    --s;
+					}
+				    }
+				}
 			    }
 
 			    if (save_arg != NULL)   /* number for 'whichwrap' */