diff --git a/misc.c b/misc.c
index f4dd215..b34e323 100644
--- a/misc.c
+++ b/misc.c
@@ -32,7 +32,7 @@
 #include <grp.h>
 #endif
 
-__RCSID("$MirOS: src/bin/mksh/misc.c,v 1.285 2017/10/11 23:48:36 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/misc.c,v 1.286 2017/10/12 15:17:03 tg Exp $");
 
 #define KSH_CHVT_FLAG
 #ifdef MKSH_SMALL
@@ -1664,7 +1664,7 @@ do_realpath(const char *upath)
 #ifdef MKSH_DOSPATH
 	} else if (mksh_drvltr(upath)) {
 		/* upath is a drive-relative pathname */
-		if (!getdrvwd(&ldest, ord(*upath)))
+		if (getdrvwd(&ldest, ord(*upath)))
 			return (NULL);
 		/* A:foo -> A:/cwd/foo; A: -> A:/cwd */
 		ipath = shf_smprintf(Tf_sss, ldest,
@@ -1783,7 +1783,7 @@ do_realpath(const char *upath)
 #ifdef MKSH_DOSPATH
 				/* symlink target might be drive-relative */
 				if (mksh_drvltr(ipath)) {
-					if (!getdrvwd(&ldest, ord(*ipath)))
+					if (getdrvwd(&ldest, ord(*ipath)))
 						goto notfound;
 					ip += 2;
 					goto assemble_symlink;
diff --git a/os2.c b/os2.c
index 4c191a6..042dd78 100644
--- a/os2.c
+++ b/os2.c
@@ -33,7 +33,7 @@
 #include <unistd.h>
 #include <process.h>
 
-__RCSID("$MirOS: src/bin/mksh/os2.c,v 1.3 2017/10/11 23:23:03 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/os2.c,v 1.4 2017/10/12 15:17:04 tg Exp $");
 
 static char *remove_trailing_dots(char *);
 static int access_stat_ex(int (*)(), const char *, void *);
@@ -564,7 +564,7 @@ cleanup(void)
 int
 getdrvwd(char **cpp, unsigned int drvltr)
 {
-	PBYTE *cp;
+	PBYTE cp;
 	ULONG sz;
 	APIRET rc;
 	ULONG drvno;
@@ -578,10 +578,10 @@ getdrvwd(char **cpp, unsigned int drvltr)
 	/* allocate 'X:/' plus sz plus NUL */
 	checkoktoadd((size_t)sz, (size_t)4);
 	cp = aresize(*cpp, (size_t)sz + (size_t)4, ATEMP);
-	cp[0] = drvltr;
+	cp[0] = ksh_toupper(drvltr);
 	cp[1] = ':';
 	cp[2] = '/';
-	drvno = (rtt2asc(drvltr) | 0x20U) - rtt2asc('a') + 1;
+	drvno = ksh_numuc(cp[0]) + 1;
 	/* NUL is part of space within buffer passed */
 	++sz;
 	if ((rc = DosQueryCurrentDir(drvno, cp + 3, &sz)) == 0) {