diff --git a/src/include/lwip/opt.h b/src/include/lwip/opt.h
index e51f8e55..3b7222e8 100644
--- a/src/include/lwip/opt.h
+++ b/src/include/lwip/opt.h
@@ -1717,7 +1717,7 @@
 #endif
 
 /**
- * MSCHAP_SUPPORT==1: Support MSCHAP. CURRENTLY NOT SUPPORTED! DO NOT SET!
+ * MSCHAP_SUPPORT==1: Support MSCHAP.
  */
 #ifndef MSCHAP_SUPPORT
 #define MSCHAP_SUPPORT                  0
diff --git a/src/netif/ppp/auth.c b/src/netif/ppp/auth.c
index 39f8aab9..af43c0d2 100644
--- a/src/netif/ppp/auth.c
+++ b/src/netif/ppp/auth.c
@@ -222,13 +222,13 @@ bool cryptpap = 0;		/* Passwords in pap-secrets are encrypted */
 //bool refuse_pap = 0;		/* Don't wanna auth. ourselves with PAP */
 //bool refuse_chap = 0;		/* Don't wanna auth. ourselves with CHAP */
 //bool refuse_eap = 0;		/* Don't wanna auth. ourselves with EAP */
-#ifdef CHAPMS
+#if MSCHAP_SUPPORT
 //bool refuse_mschap = 0;		/* Don't wanna auth. ourselves with MS-CHAP */
 //bool refuse_mschap_v2 = 0;	/* Don't wanna auth. oif 0 /* UNUSED */urselves with MS-CHAPv2 */
-#else
+#else /* MSCHAP_SUPPORT */
 //bool refuse_mschap = 1;		/* Don't wanna auth. ourselves with MS-CHAP */
 //bool refuse_mschap_v2 = 1;	/* Don't wanna auth. ourselves with MS-CHAPv2 */
-#endif
+#endif /* MSCHAP_SUPPORT */
 #endif /* MOVED TO ppp_settings */
 #if 0 /* UNUSED */
 bool usehostname = 0;		/* Use hostname for our_name */
@@ -301,7 +301,7 @@ option_t auth_options[] = {
       "Require CHAP authentication from peer",
       OPT_ALIAS | OPT_PRIOSUB | OPT_A2OR | MDTYPE_MD5,
       &lcp_wantoptions[0].chap_mdtype },
-#ifdef CHAPMS
+#if MSCHAP_SUPPORT
     { "require-mschap", o_bool, &auth_required,
       "Require MS-CHAP authentication from peer",
       OPT_PRIOSUB | OPT_A2OR | MDTYPE_MICROSOFT,
@@ -318,7 +318,7 @@ option_t auth_options[] = {
       "Require MS-CHAPv2 authentication from peer",
       OPT_ALIAS | OPT_PRIOSUB | OPT_A2OR | MDTYPE_MICROSOFT_V2,
       &lcp_wantoptions[0].chap_mdtype },
-#endif
+#endif /* MSCHAP_SUPPORT */
 #if 0
     { "refuse-pap", o_bool, &refuse_pap,
       "Don't agree to auth to peer with PAP", 1 },
@@ -333,7 +333,7 @@ option_t auth_options[] = {
       OPT_ALIAS | OPT_A2CLRB | MDTYPE_MD5,
       &lcp_allowoptions[0].chap_mdtype },
 #endif
-#ifdef CHAPMS
+#if MSCHAP_SUPPORT
 #if 0
     { "refuse-mschap", o_bool, &refuse_mschap,
       "Don't agree to auth to peer with MS-CHAP",
@@ -352,7 +352,7 @@ option_t auth_options[] = {
       OPT_ALIAS | OPT_A2CLRB | MDTYPE_MICROSOFT_V2,
       &lcp_allowoptions[0].chap_mdtype },
 #endif
-#endif
+#endif /* MSCHAP_SUPPORT*/
 #if EAP_SUPPORT
     { "require-eap", o_bool, &lcp_wantoptions[0].neg_eap,
       "Require EAP authentication from peer", OPT_PRIOSUB | 1,
@@ -973,14 +973,14 @@ auth_peer_success(unit, protocol, prot_flavor, name, namelen)
 	case CHAP_MD5:
 	    bit |= CHAP_MD5_PEER;
 	    break;
-#ifdef CHAPMS
+#if MSCHAP_SUPPORT
 	case CHAP_MICROSOFT:
 	    bit |= CHAP_MS_PEER;
 	    break;
 	case CHAP_MICROSOFT_V2:
 	    bit |= CHAP_MS2_PEER;
 	    break;
-#endif
+#endif /* MSCHAP_SUPPORT */
 	}
 	break;
     case PPP_PAP:
@@ -1049,14 +1049,14 @@ auth_withpeer_success(unit, protocol, prot_flavor)
 	case CHAP_MD5:
 	    bit |= CHAP_MD5_WITHPEER;
 	    break;
-#ifdef CHAPMS
+#if MSCHAP_SUPPORT
 	case CHAP_MICROSOFT:
 	    bit |= CHAP_MS_WITHPEER;
 	    break;
 	case CHAP_MICROSOFT_V2:
 	    bit |= CHAP_MS2_WITHPEER;
 	    break;
-#endif
+#endif /* MSCHAP_SUPPORT */
 	}
 	break;
     case PPP_PAP:
@@ -1381,10 +1381,12 @@ auth_reset(unit)
     ao->chap_mdtype = MDTYPE_NONE;
     if(!ppp_settings.refuse_chap)
       ao->chap_mdtype |= MDTYPE_MD5;
+#if MSCHAP_SUPPORT
     if(!ppp_settings.refuse_mschap)
       ao->chap_mdtype |= MDTYPE_MICROSOFT;
     if(!ppp_settings.refuse_mschap_v2)
       ao->chap_mdtype |= MDTYPE_MICROSOFT_V2;
+#endif /* MSCHAP_SUPPORT */
 
     ao->neg_chap = (ao->chap_mdtype != MDTYPE_NONE);
 
@@ -1401,8 +1403,10 @@ auth_reset(unit)
   printf("neg_upap: %d\n", ao->neg_upap);
   printf("neg_chap: %d\n", ao->neg_chap);
   printf("neg_chap_md5: %d\n", !!(ao->chap_mdtype&MDTYPE_MD5) );
+#if MSCHAP_SUPPORT
   printf("neg_chap_ms: %d\n", !!(ao->chap_mdtype&MDTYPE_MICROSOFT) );
   printf("neg_chap_ms2: %d\n", !!(ao->chap_mdtype&MDTYPE_MICROSOFT_V2) );
+#endif /* MSCHAP_SUPPORT */
 #if EAP_SUPPORT
   printf("neg_eap: %d\n", ao->neg_eap);
 #endif /* EAP_SUPPORT */
diff --git a/src/netif/ppp/chap-new.c b/src/netif/ppp/chap-new.c
index 90d9e289..f3b612e8 100644
--- a/src/netif/ppp/chap-new.c
+++ b/src/netif/ppp/chap-new.c
@@ -40,7 +40,7 @@
 #include "chap-new.h"
 #include "chap-md5.h"
 
-#ifdef CHAPMS
+#if MSCHAP_SUPPORT
 #include "chap_ms.h"
 #define MDTYPE_ALL (MDTYPE_MICROSOFT_V2 | MDTYPE_MICROSOFT | MDTYPE_MD5)
 #else
@@ -149,7 +149,7 @@ chap_init(int unit)
 	memset(&server, 0, sizeof(server));
 
 	chap_md5_init();
-#ifdef CHAPMS
+#if MSCHAP_SUPPORT
 	chapms_init();
 #endif
 }
diff --git a/src/netif/ppp/chap-new.h b/src/netif/ppp/chap-new.h
index 48235d40..02e9b06a 100644
--- a/src/netif/ppp/chap-new.h
+++ b/src/netif/ppp/chap-new.h
@@ -28,6 +28,8 @@
  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
+#include "lwip/opt.h"
+
 /*
  * CHAP packets begin with a standard header with code, id, len (2 bytes).
  */
@@ -45,8 +47,10 @@
  * CHAP digest codes.
  */
 #define CHAP_MD5		5
+#if MSCHAP_SUPPORT
 #define CHAP_MICROSOFT		0x80
 #define CHAP_MICROSOFT_V2	0x81
+#endif /* MSCHAP_SUPPORT */
 
 /*
  * Semi-arbitrary limits on challenge and response fields.
@@ -55,37 +59,57 @@
 #define MAX_RESPONSE_LEN	64
 
 /* bitmask of supported algorithms */
+#if MSCHAP_SUPPORT
 #define MDTYPE_MICROSOFT_V2	0x1
 #define MDTYPE_MICROSOFT	0x2
+#endif /* MSCHAP_SUPPORT */
 #define MDTYPE_MD5		0x4
 #define MDTYPE_NONE		0
 
 /* hashes supported by this instance of pppd */
 extern int chap_mdtype_all;
 
+#if MSCHAP_SUPPORT
 /* Return the digest alg. ID for the most preferred digest type. */
 #define CHAP_DIGEST(mdtype) \
     ((mdtype) & MDTYPE_MD5)? CHAP_MD5: \
     ((mdtype) & MDTYPE_MICROSOFT_V2)? CHAP_MICROSOFT_V2: \
     ((mdtype) & MDTYPE_MICROSOFT)? CHAP_MICROSOFT: \
     0
+#else /* !MSCHAP_SUPPORT */
+#define CHAP_DIGEST(mdtype) \
+    ((mdtype) & MDTYPE_MD5)? CHAP_MD5: \
+    0
+#endif /* MSCHAP_SUPPORT */
 
 /* Return the bit flag (lsb set) for our most preferred digest type. */
 #define CHAP_MDTYPE(mdtype) ((mdtype) ^ ((mdtype) - 1)) & (mdtype)
 
 /* Return the bit flag for a given digest algorithm ID. */
+#if MSCHAP_SUPPORT
 #define CHAP_MDTYPE_D(digest) \
     ((digest) == CHAP_MICROSOFT_V2)? MDTYPE_MICROSOFT_V2: \
     ((digest) == CHAP_MICROSOFT)? MDTYPE_MICROSOFT: \
     ((digest) == CHAP_MD5)? MDTYPE_MD5: \
     0
+#else /* !MSCHAP_SUPPORT */
+#define CHAP_MDTYPE_D(digest) \
+    ((digest) == CHAP_MD5)? MDTYPE_MD5: \
+    0
+#endif /* MSCHAP_SUPPORT */
 
 /* Can we do the requested digest? */
+#if MSCHAP_SUPPORT
 #define CHAP_CANDIGEST(mdtype, digest) \
     ((digest) == CHAP_MICROSOFT_V2)? (mdtype) & MDTYPE_MICROSOFT_V2: \
     ((digest) == CHAP_MICROSOFT)? (mdtype) & MDTYPE_MICROSOFT: \
     ((digest) == CHAP_MD5)? (mdtype) & MDTYPE_MD5: \
     0
+#else /* !MSCHAP_SUPPORT */
+#define CHAP_CANDIGEST(mdtype, digest) \
+    ((digest) == CHAP_MD5)? (mdtype) & MDTYPE_MD5: \
+    0
+#endif /* MSCHAP_SUPPORT */
 
 /*
  * The code for each digest type has to supply one of these.
diff --git a/src/netif/ppp/chap_ms.c b/src/netif/ppp/chap_ms.c
index e19b2a16..f3691bd3 100644
--- a/src/netif/ppp/chap_ms.c
+++ b/src/netif/ppp/chap_ms.c
@@ -75,10 +75,7 @@
  */
 
 #include "lwip/opt.h"
-
-#define RCSID	"$Id: chap_ms.c,v 1.38 2007/12/01 20:10:51 carlsonj Exp $"
-
-#ifdef CHAPMS
+#if PPP_SUPPORT && MSCHAP_SUPPORT  /* don't build if not configured for use in lwipopts.h */
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -97,8 +94,6 @@
 #include "pppcrypt.h"
 #include "magic.h"
 
-static const char rcsid[] = RCSID;
-
 #define SHA1_SIGNATURE_SIZE 20
 
 static void	ascii2unicode __P((char[], int, u_char[]));
@@ -947,4 +942,4 @@ chapms_init(void)
 #endif /* PPP_OPTIONS */
 }
 
-#endif /* CHAPMS */
+#endif /* PPP_SUPPORT && MSCHAP_SUPPORT */
diff --git a/src/netif/ppp/chap_ms.h b/src/netif/ppp/chap_ms.h
index 040d80ad..ffff9b66 100644
--- a/src/netif/ppp/chap_ms.h
+++ b/src/netif/ppp/chap_ms.h
@@ -30,6 +30,9 @@
  * $Id: chap_ms.h,v 1.13 2004/11/15 22:13:26 paulus Exp $
  */
 
+#include "lwip/opt.h"
+#if PPP_SUPPORT && MSCHAP_SUPPORT  /* don't build if not configured for use in lwipopts.h */
+
 #ifndef __CHAPMS_INCLUDE__
 
 #define MD4_SIGNATURE_SIZE	16	/* 16 bytes in a MD4 message digest */
@@ -107,3 +110,5 @@ void chapms_init(void);
 
 #define __CHAPMS_INCLUDE__
 #endif /* __CHAPMS_INCLUDE__ */
+
+#endif /* PPP_SUPPORT && MSCHAP_SUPPORT */
diff --git a/src/netif/ppp/lcp.c b/src/netif/ppp/lcp.c
index ab922637..7dfc6a74 100644
--- a/src/netif/ppp/lcp.c
+++ b/src/netif/ppp/lcp.c
@@ -2177,6 +2177,7 @@ lcp_printpkt(p, plen, printer, arg)
 				printer(arg, " MD5");
 				++p;
 				break;
+#if MSCHAP_SUPPORT
 			    case CHAP_MICROSOFT:
 				printer(arg, " MS");
 				++p;
@@ -2186,6 +2187,7 @@ lcp_printpkt(p, plen, printer, arg)
 				printer(arg, " MS-v2");
 				++p;
 				break;
+#endif /* MSCHAP_SUPPORT */
 			    }
 			}
 			break;
diff --git a/src/netif/ppp/pppd.h b/src/netif/ppp/pppd.h
index 374f4319..3ac8ceb4 100644
--- a/src/netif/ppp/pppd.h
+++ b/src/netif/ppp/pppd.h
@@ -365,11 +365,13 @@ extern bool	ms_lanman;	/* Use LanMan password instead of NT */
 /* Values for auth_done only */
 #define CHAP_MD5_WITHPEER	0x40
 #define CHAP_MD5_PEER		0x80
+#if MSCHAP_SUPPORT
 #define CHAP_MS_SHIFT		8	/* LSB position for MS auths */
 #define CHAP_MS_WITHPEER	0x100
 #define CHAP_MS_PEER		0x200
 #define CHAP_MS2_WITHPEER	0x400
 #define CHAP_MS2_PEER		0x800
+#endif /* MSCHAP_SUPPORT */
 
 extern char *current_option;	/* the name of the option being parsed */
 extern int  privileged_option;	/* set iff the current option came from root */
diff --git a/src/netif/ppp/pppmy.c b/src/netif/ppp/pppmy.c
index c0b20570..4efcc982 100644
--- a/src/netif/ppp/pppmy.c
+++ b/src/netif/ppp/pppmy.c
@@ -435,10 +435,17 @@ int ppp_init(void) {
 void
 pppSetAuth(enum pppAuthType authType, const char *user, const char *passwd)
 {
+  /* FIXME: the following may look stupid, but this is just an easy way
+   * to check different auth by changing compile time option
+   */
+  ppp_settings.refuse_pap = 1;
+  ppp_settings.refuse_chap = 0;
+#if MSCHAP_SUPPORT
   ppp_settings.refuse_pap = 1;
   ppp_settings.refuse_chap = 1;
   ppp_settings.refuse_mschap = 1;
   ppp_settings.refuse_mschap_v2 = 0;
+#endif /* MSCHAP_SUPPORT */
 #if EAP_SUPPORT
   ppp_settings.refuse_pap = 1;
   ppp_settings.refuse_chap = 1;
diff --git a/src/netif/ppp/pppmy.h b/src/netif/ppp/pppmy.h
index 042410df..f082f460 100644
--- a/src/netif/ppp/pppmy.h
+++ b/src/netif/ppp/pppmy.h
@@ -5,6 +5,8 @@
  *      Author: gradator
  */
 
+#include "lwip/opt.h"
+
 #ifndef PPPMY_H_
 #define PPPMY_H_
 
@@ -46,8 +48,10 @@ struct ppp_settings {
   u_int  explicit_remote   : 1;       /* remote_name specified with remotename opt */
   u_int  refuse_pap        : 1;       /* Don't wanna auth. ourselves with PAP */
   u_int  refuse_chap       : 1;       /* Don't wanna auth. ourselves with CHAP */
+#if MSCHAP_SUPPORT
   u_int  refuse_mschap     : 1;       /* Don't wanna auth. ourselves with MS-CHAP */
   u_int  refuse_mschap_v2  : 1;       /* Don't wanna auth. ourselves with MS-CHAPv2 */
+#endif /* MSCHAP_SUPPORT */
 #if EAP_SUPPORT
   u_int  refuse_eap        : 1;       /* Don't wanna auth. ourselves with EAP */
 #endif /* EAP_SUPPORT */