--- a/src/ex_cmds2.c
+++ b/src/ex_cmds2.c
@@ -3691,14 +3691,17 @@ source_all_matches(char_u *pat)
 add_pack_dir_to_rtp(char_u *fname)
 {
     char_u  *p4, *p3, *p2, *p1, *p;
-    char_u  *insp;
+    char_u  *entry;
+    char_u  *insp = NULL;
     int	    c;
     char_u  *new_rtp;
     int	    keep;
     size_t  oldlen;
     size_t  addlen;
+    size_t  new_rtp_len;
     char_u  *afterdir = NULL;
     size_t  afterlen = 0;
+    char_u  *after_insp = NULL;
     char_u  *ffname = NULL;
     size_t  fname_len;
     char_u  *buf = NULL;
@@ -3725,54 +3728,99 @@ add_pack_dir_to_rtp(char_u *fname)
     if (ffname == NULL)
 	return FAIL;
 
-    /* Find "ffname" in "p_rtp", ignoring '/' vs '\' differences. */
+    // Find "ffname" in "p_rtp", ignoring '/' vs '\' differences.
+    // Also stop at the first "after" directory.
     fname_len = STRLEN(ffname);
-    insp = p_rtp;
     buf = alloc(MAXPATHL);
     if (buf == NULL)
 	goto theend;
-    while (*insp != NUL)
+    for (entry = p_rtp; *entry != NUL; )
     {
-	copy_option_part(&insp, buf, MAXPATHL, ",");
-	add_pathsep(buf);
-	rtp_ffname = fix_fname(buf);
-	if (rtp_ffname == NULL)
-	    goto theend;
-	match = vim_fnamencmp(rtp_ffname, ffname, fname_len) == 0;
-	vim_free(rtp_ffname);
-	if (match)
+	char_u *cur_entry = entry;
+
+	copy_option_part(&entry, buf, MAXPATHL, ",");
+	if (insp == NULL)
+	{
+	    add_pathsep(buf);
+	    rtp_ffname = fix_fname(buf);
+	    if (rtp_ffname == NULL)
+		goto theend;
+	    match = vim_fnamencmp(rtp_ffname, ffname, fname_len) == 0;
+	    vim_free(rtp_ffname);
+	    if (match)
+		// Insert "ffname" after this entry (and comma).
+		insp = entry;
+	}
+
+	if ((p = (char_u *)strstr((char *)buf, "after")) != NULL
+		&& p > buf
+		&& vim_ispathsep(p[-1])
+		&& (vim_ispathsep(p[5]) || p[5] == NUL || p[5] == ','))
+	{
+	    if (insp == NULL)
+		// Did not find "ffname" before the first "after" directory,
+		// insert it before this entry.
+		insp = cur_entry;
+	    after_insp = cur_entry;
 	    break;
+	}
     }
 
-    if (*insp == NUL)
-	/* not found, append at the end */
+    if (insp == NULL)
+	// Both "fname" and "after" not found, append at the end.
 	insp = p_rtp + STRLEN(p_rtp);
-    else
-	/* append after the matching directory. */
-	--insp;
-
-    /* check if rtp/pack/name/start/name/after exists */
+
+    // check if rtp/pack/name/start/name/after exists
     afterdir = concat_fnames(fname, (char_u *)"after", TRUE);
     if (afterdir != NULL && mch_isdir(afterdir))
-	afterlen = STRLEN(afterdir) + 1; /* add one for comma */
+	afterlen = STRLEN(afterdir) + 1; // add one for comma
 
     oldlen = STRLEN(p_rtp);
-    addlen = STRLEN(fname) + 1; /* add one for comma */
-    new_rtp = alloc((int)(oldlen + addlen + afterlen + 1));
-    /* add one for NUL */
+    addlen = STRLEN(fname) + 1; // add one for comma
+    new_rtp = alloc((int)(oldlen + addlen + afterlen + 1)); // add one for NUL
     if (new_rtp == NULL)
 	goto theend;
+
+    // We now have 'rtp' parts: {keep}{keep_after}{rest}.
+    // Create new_rtp, first: {keep},{fname}
     keep = (int)(insp - p_rtp);
     mch_memmove(new_rtp, p_rtp, keep);
-    new_rtp[keep] = ',';
-    mch_memmove(new_rtp + keep + 1, fname, addlen);
+    new_rtp_len = keep;
+    if (*insp == NUL)
+	new_rtp[new_rtp_len++] = ',';  // add comma before
+    mch_memmove(new_rtp + new_rtp_len, fname, addlen - 1);
+    new_rtp_len += addlen - 1;
+    if (*insp != NUL)
+	new_rtp[new_rtp_len++] = ',';  // add comma after
+
+    if (afterlen > 0 && after_insp != NULL)
+    {
+	int keep_after = (int)(after_insp - p_rtp);
+
+	// Add to new_rtp: {keep},{fname}{keep_after},{afterdir}
+	mch_memmove(new_rtp + new_rtp_len, p_rtp + keep,
+							keep_after - keep);
+	new_rtp_len += keep_after - keep;
+	mch_memmove(new_rtp + new_rtp_len, afterdir, afterlen - 1);
+	new_rtp_len += afterlen - 1;
+	new_rtp[new_rtp_len++] = ',';
+	keep = keep_after;
+    }
+
     if (p_rtp[keep] != NUL)
-	mch_memmove(new_rtp + keep + addlen, p_rtp + keep, oldlen - keep + 1);
-    if (afterlen > 0)
+	// Append rest: {keep},{fname}{keep_after},{afterdir}{rest}
+	mch_memmove(new_rtp + new_rtp_len, p_rtp + keep, oldlen - keep + 1);
+    else
+	new_rtp[new_rtp_len] = NUL;
+
+    if (afterlen > 0 && after_insp == NULL)
     {
+	// Append afterdir when "after" was not found:
+	// {keep},{fname}{rest},{afterdir}
 	STRCAT(new_rtp, ",");
 	STRCAT(new_rtp, afterdir);
     }
+
     set_option_value((char_u *)"rtp", 0L, new_rtp, 0);
     vim_free(new_rtp);
     retval = OK;