diff --git a/src/ex_cmds2.c b/src/ex_cmds2.c
index e6ef381..e255a13 100644
--- a/src/ex_cmds2.c
+++ b/src/ex_cmds2.c
@@ -3349,6 +3349,7 @@
     char_u  *afterdir;
     size_t  afterlen = 0;
     char_u  *ffname = fix_fname(fname);
+    int	    fname_len;
 
     if (ffname == NULL)
 	return;
@@ -3369,7 +3370,20 @@
 	 * find the part up to "pack" in 'runtimepath' */
 	c = *p4;
 	*p4 = NUL;
-	insp = (char_u *)strstr((char *)p_rtp, (char *)ffname);
+
+	/* Find "ffname" in "p_rtp", ignoring '/' vs '\' differences. */
+	fname_len = STRLEN(ffname);
+	insp = p_rtp;
+	for (;;)
+	{
+	    if (vim_fnamencmp(insp, ffname, fname_len) == 0)
+		break;
+	    insp = vim_strchr(insp, ',');
+	    if (insp == NULL)
+		break;
+	    ++insp;
+	}
+
 	if (insp == NULL)
 	    /* not found, append at the end */
 	    insp = p_rtp + STRLEN(p_rtp);