diff --git a/Makefile.in b/Makefile.in
index d084fca..9d61685 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -46,12 +46,18 @@ SOURCES:= dtls.c crypto.c ccm.c hmac.c netq.c peer.c dtls_time.c
 ifneq ("@NDEBUG@", "1")
 SOURCES += debug.c
 endif
-OBJECTS:= $(patsubst %.c, %.o, $(SOURCES)) aes/rijndael.o ecc/ecc.o @OPT_OBJS@
+OBJECTS:= $(patsubst %.c, %.o, $(SOURCES)) aes/rijndael.o @OPT_OBJS@
+ifeq ("@DTLS_ECC@", "1")
+OBJECTS += ecc/ecc.o
+endif
 HEADERS:=dtls.h hmac.h debug.h config.h uthash.h numeric.h crypto.h global.h ccm.h \
  netq.h t_list.h alert.h utlist.h prng.h peer.h state.h dtls_time.h
 CFLAGS:=-Wall -pedantic -std=c99 @CFLAGS@
 CPPFLAGS:=@CPPFLAGS@ -DDTLS_CHECK_CONTENTTYPE
-SUBDIRS:=tests doc sha2 aes ecc
+SUBDIRS:=tests doc sha2 aes
+ifeq ("@DTLS_ECC@", "1")
+SUBDIRS += ecc
+endif
 DISTDIR=$(top_builddir)/$(package)
 FILES:=Makefile.in configure configure.in config.h.in $(SOURCES) $(HEADERS)
 LIB:=libtinydtls.a
diff --git a/Makefile.tinydtls b/Makefile.tinydtls
index 5b68995..3a684a2 100644
--- a/Makefile.tinydtls
+++ b/Makefile.tinydtls
@@ -21,5 +21,16 @@ CFLAGS += -DSHA2_USE_INTTYPES_H=1
 endif
 
 CFLAGS += -DDTLSv12 -DWITH_SHA256 
+tinydtls_src = dtls.c crypto.c hmac.c rijndael.c sha2.c ccm.c netq.c ecc.c dtls_time.c peer.c
+
+# This adds support for TLS_PSK_WITH_AES_128_CCM_8
+CFLAGS += -DDTLS_PSK
+
+# This adds support for TLS_ECDHE_ECDSA_WITH_AES_128_CCM_8
+CFLAGS += -DDTLS_ECC
+tinydtls_src += ecc.c
+
+# This activates debugging support
+# CFLAGS += -DNDEBUG
+tinydtls_src += debug.c
 
-tinydtls_src = dtls.c crypto.c hmac.c rijndael.c sha2.c ccm.c netq.c debug.c ecc.c dtls_time.c peer.c
diff --git a/configure.in b/configure.in
index 04a5603..374e470 100644
--- a/configure.in
+++ b/configure.in
@@ -58,11 +58,26 @@ AC_ARG_WITH(debug,
    NDEBUG=1], 
   [])
 
+
+AC_ARG_WITH(ecc,
+  [AS_HELP_STRING([--without-ecc],[disable support for TLS_ECDHE_ECDSA_WITH_AES_128_CCM_8])],
+  [],
+  [CPPFLAGS="${CPPFLAGS} -DDTLS_ECC"
+   DTLS_ECC=1])
+
+AC_ARG_WITH(psk,
+  [AS_HELP_STRING([--without-psk],[disable support for TLS_PSK_WITH_AES_128_CCM_8])],
+  [],
+  [CPPFLAGS="${CPPFLAGS} -DDTLS_PSK"
+   DTLS_PSK=1])
+
 CPPFLAGS="${CPPFLAGS} -DDTLSv12 -DWITH_SHA256"
 OPT_OBJS="${OPT_OBJS} sha2/sha2.o"
 
 AC_SUBST(OPT_OBJS)
 AC_SUBST(NDEBUG)
+AC_SUBST(DTLS_ECC)
+AC_SUBST(DTLS_PSK)
 
 # Checks for header files.
 AC_CHECK_HEADERS([assert.h arpa/inet.h fcntl.h inttypes.h netdb.h netinet/in.h stddef.h stdint.h stdlib.h string.h strings.h sys/param.h sys/socket.h sys/time.h time.h unistd.h])
diff --git a/crypto.c b/crypto.c
index 474daca..6293bd3 100644
--- a/crypto.c
+++ b/crypto.c
@@ -307,6 +307,7 @@ dtls_ccm_decrypt(aes128_ccm_t *ccm_ctx, const unsigned char *src,
   return len;
 }
 
+#ifdef DTLS_PSK
 int
 dtls_psk_pre_master_secret(unsigned char *key, size_t keylen,
 			   unsigned char *result, size_t result_len) {
@@ -329,7 +330,9 @@ dtls_psk_pre_master_secret(unsigned char *key, size_t keylen,
 
   return 2 * (sizeof(uint16) + keylen);
 }
+#endif /* DTLS_PSK */
 
+#ifdef DTLS_ECC
 static void dtls_ec_key_to_uint32(const unsigned char *key, size_t key_size,
 				  uint32_t *result) {
   int i;
@@ -509,6 +512,7 @@ dtls_ecdsa_verify_sig(const unsigned char *pub_key_x,
   return dtls_ecdsa_verify_sig_hash(pub_key_x, pub_key_y, key_size, sha256hash,
 				    sizeof(sha256hash), result_r, result_s);
 }
+#endif /* DTLS_ECC */
 
 int 
 dtls_encrypt(const unsigned char *src, size_t length,
diff --git a/crypto.h b/crypto.h
index 14fbe1f..f516a7a 100644
--- a/crypto.h
+++ b/crypto.h
@@ -121,8 +121,12 @@ typedef struct {
   dtls_cipher_t cipher;		/**< cipher type */
   unsigned int do_client_auth:1;
   union {
+#ifdef DTLS_ECC
     dtls_handshake_parameters_ecdsa_t ecdsa;
+#endif /* DTLS_ECC */
+#ifdef DTLS_PSK
     dtls_handshake_parameters_psk_t psk;
+#endif /* DTLS_PSK */
   } keyx;
 } dtls_handshake_parameters_t;
 
diff --git a/dtls-client.c b/dtls-client.c
index 43bb1d2..dab3008 100644
--- a/dtls-client.c
+++ b/dtls-client.c
@@ -115,6 +115,7 @@ send_to_peer(struct dtls_context_t *ctx,
   return len;
 }
 
+#ifdef DTLS_PSK
 static int
 get_psk_key(struct dtls_context_t *ctx, 
 	    const session_t *session, 
@@ -131,7 +132,9 @@ get_psk_key(struct dtls_context_t *ctx,
   *result = &psk;
   return 0;
 }
+#endif /* DTLS_PSK */
 
+#ifdef DTLS_ECC
 static int
 get_ecdsa_key(struct dtls_context_t *ctx,
 	      const session_t *session,
@@ -155,6 +158,7 @@ verify_ecdsa_key(struct dtls_context_t *ctx,
 		 size_t key_size) {
   return 0;
 }
+#endif /* DTLS_ECC */
 
 PROCESS(udp_server_process, "UDP server process");
 AUTOSTART_PROCESSES(&udp_server_process);
@@ -216,9 +220,13 @@ init_dtls(session_t *dst) {
     .write = send_to_peer,
     .read  = read_from_peer,
     .event = NULL,
+#ifdef DTLS_PSK
     .get_psk_key = get_psk_key,
+#endif /* DTLS_PSK */
+#ifdef DTLS_ECC
     .get_ecdsa_key = get_ecdsa_key,
     .verify_ecdsa_key = verify_ecdsa_key
+#endif /* DTLS_ECC */
   };
   PRINTF("DTLS client started\n");
 
diff --git a/dtls-server.c b/dtls-server.c
index 1ba53bb..bb6d83d 100644
--- a/dtls-server.c
+++ b/dtls-server.c
@@ -106,6 +106,7 @@ send_to_peer(struct dtls_context_t *ctx,
   return len;
 }
 
+#ifdef DTLS_PSK
 static int
 get_psk_key(struct dtls_context_t *ctx, 
 	    const session_t *session, 
@@ -122,7 +123,9 @@ get_psk_key(struct dtls_context_t *ctx,
   *result = &psk;
   return 0;
 }
+#endif /* DTLS_PSK */
 
+#ifdef DTLS_ECC
 static int
 get_ecdsa_key(struct dtls_context_t *ctx,
 	      const session_t *session,
@@ -146,6 +149,7 @@ verify_ecdsa_key(struct dtls_context_t *ctx,
 		 size_t key_size) {
   return 0;
 }
+#endif /* DTLS_ECC */
 
 PROCESS(udp_server_process, "UDP server process");
 AUTOSTART_PROCESSES(&udp_server_process);
@@ -208,9 +212,13 @@ init_dtls() {
     .write = send_to_peer,
     .read  = read_from_peer,
     .event = NULL,
+#ifdef DTLS_PSK
     .get_psk_key = get_psk_key,
+#endif /* DTLS_PSK */
+#ifdef DTLS_ECC
     .get_ecdsa_key = get_ecdsa_key,
     .verify_ecdsa_key = verify_ecdsa_key
+#endif /* DTLS_ECC */
   };
 #if UIP_CONF_ROUTER
   uip_ipaddr_t ipaddr;
diff --git a/dtls.c b/dtls.c
index 53a04da..37eca92 100644
--- a/dtls.c
+++ b/dtls.c
@@ -433,25 +433,48 @@ static uint8 compression_methods[] = {
 
 static inline int is_tls_ecdhe_ecdsa_with_aes_128_ccm_8(dtls_cipher_t cipher)
 {
+#ifdef DTLS_ECC
   return cipher == TLS_ECDHE_ECDSA_WITH_AES_128_CCM_8;
+#else
+  return 0;
+#endif /* DTLS_ECC */
 }
 
 static inline int is_tls_psk_with_aes_128_ccm_8(dtls_cipher_t cipher)
 {
+#ifdef DTLS_PSK
   return cipher == TLS_PSK_WITH_AES_128_CCM_8;
+#else
+  return 0;
+#endif /* DTLS_PSK */
 }
 
-static inline int is_psk_supported(dtls_context_t *ctx){
+static inline int is_psk_supported(dtls_context_t *ctx)
+{
+#ifdef DTLS_PSK
   return ctx && ctx->h && ctx->h->get_psk_key;
+#else
+  return 0;
+#endif /* DTLS_PSK */
 }
 
-static inline int is_ecdsa_supported(dtls_context_t *ctx, int is_client){
+static inline int is_ecdsa_supported(dtls_context_t *ctx, int is_client)
+{
+#ifdef DTLS_ECC
   return ctx && ctx->h && ((!is_client && ctx->h->get_ecdsa_key) || 
 			   (is_client && ctx->h->verify_ecdsa_key));
+#else
+  return 0;
+#endif /* DTLS_ECC */
 }
 
-static inline int is_ecdsa_client_auth_supported(dtls_context_t *ctx) {
+static inline int is_ecdsa_client_auth_supported(dtls_context_t *ctx)
+{
+#ifdef DTLS_ECC
   return ctx && ctx->h && ctx->h->get_ecdsa_key && ctx->h->verify_ecdsa_key;
+#else
+  return 0;
+#endif /* DTLS_ECC */
 }
 
 /**
@@ -512,7 +535,6 @@ calculate_key_block(dtls_context_t *ctx,
   int pre_master_len = 0;
   dtls_security_parameters_t *security = dtls_security_params_next(peer);
   uint8 master_secret[DTLS_MASTER_SECRET_LENGTH];
-  int err;
 
   if (!security) {
     return dtls_alert_fatal_create(DTLS_ALERT_INTERNAL_ERROR);
@@ -521,8 +543,10 @@ calculate_key_block(dtls_context_t *ctx,
   pre_master_secret = security->key_block;
 
   switch (handshake->cipher) {
+#ifdef DTLS_PSK
   case TLS_PSK_WITH_AES_128_CCM_8: {
     const dtls_psk_key_t *psk;
+    int err;
 
     err = CALL(ctx, get_psk_key, session, handshake->keyx.psk.identity,
 	       handshake->keyx.psk.id_length, &psk);
@@ -542,6 +566,8 @@ calculate_key_block(dtls_context_t *ctx,
 
     break;
   }
+#endif /* DTLS_PSK */
+#ifdef DTLS_ECC
   case TLS_ECDHE_ECDSA_WITH_AES_128_CCM_8: {
     pre_master_len = dtls_ecdh_pre_master_secret(handshake->keyx.ecdsa.own_eph_priv,
 						 handshake->keyx.ecdsa.other_eph_pub_x,
@@ -555,6 +581,7 @@ calculate_key_block(dtls_context_t *ctx,
     }
     break;
   }
+#endif /* DTLS_ECC */
   default:
     dtls_crit("calculate_key_block: unknown cipher\n");
     return dtls_alert_fatal_create(DTLS_ALERT_INTERNAL_ERROR);
@@ -896,6 +923,7 @@ check_client_keyexchange(dtls_context_t *ctx,
 			 dtls_handshake_parameters_t *handshake,
 			 uint8 *data, size_t length) {
 
+#ifdef DTLS_ECC
   if (is_tls_ecdhe_ecdsa_with_aes_128_ccm_8(handshake->cipher)) {
 
     if (length < DTLS_HS_LENGTH + DTLS_CKXEC_LENGTH) {
@@ -923,7 +951,10 @@ check_client_keyexchange(dtls_context_t *ctx,
     memcpy(handshake->keyx.ecdsa.other_eph_pub_y, data,
 	   sizeof(handshake->keyx.ecdsa.other_eph_pub_y));
     data += sizeof(handshake->keyx.ecdsa.other_eph_pub_y);
-  } else {
+  }
+#endif /* DTLS_ECC */
+#ifdef DTLS_PSK
+  if (is_tls_psk_with_aes_128_ccm_8(handshake->cipher)) {
     int id_length;
 
     if (length < DTLS_HS_LENGTH + DTLS_CKXPSK_LENGTH_MIN) {
@@ -948,6 +979,7 @@ check_client_keyexchange(dtls_context_t *ctx,
     handshake->keyx.psk.id_length = id_length;
     memcpy(handshake->keyx.psk.identity, data, id_length);
   }
+#endif /* DTLS_PSK */
   return 0;
 }
 
@@ -1462,6 +1494,7 @@ dtls_verify_peer(dtls_context_t *ctx,
 #undef mycookie
 }
 
+#ifdef DTLS_ECC
 static int
 dtls_check_ecdsa_signature_elem(uint8 *data, size_t data_length,
 				unsigned char **result_r,
@@ -1585,6 +1618,7 @@ check_client_certificate_verify(dtls_context_t *ctx,
   }
   return 0;
 }
+#endif /* DTLS_ECC */
 
 static int
 dtls_send_server_hello(dtls_context_t *ctx, dtls_peer_t *peer)
@@ -1684,6 +1718,7 @@ dtls_send_server_hello(dtls_context_t *ctx, dtls_peer_t *peer)
 				 buf, p - buf);
 }
 
+#ifdef DTLS_ECC
 static int
 dtls_send_certificate_ecdsa(dtls_context_t *ctx, dtls_peer_t *peer,
 			    const dtls_ecdsa_key_t *key)
@@ -1836,7 +1871,9 @@ dtls_send_server_key_exchange_ecdh(dtls_context_t *ctx, dtls_peer_t *peer,
   return dtls_send_handshake_msg(ctx, peer, DTLS_HT_SERVER_KEY_EXCHANGE,
 				 buf, p - buf);
 }
+#endif /* DTLS_ECC */
 
+#ifdef DTLS_PSK
 static int
 dtls_send_server_key_exchange_psk(dtls_context_t *ctx, dtls_peer_t *peer,
 				   const dtls_psk_key_t *key)
@@ -1862,7 +1899,9 @@ dtls_send_server_key_exchange_psk(dtls_context_t *ctx, dtls_peer_t *peer,
   return dtls_send_handshake_msg(ctx, peer, DTLS_HT_SERVER_KEY_EXCHANGE,
 				 buf, p - buf);
 }
+#endif /* DTLS_PSK */
 
+#ifdef DTLS_ECC
 static int
 dtls_send_server_certificate_request(dtls_context_t *ctx, dtls_peer_t *peer)
 {
@@ -1903,6 +1942,7 @@ dtls_send_server_certificate_request(dtls_context_t *ctx, dtls_peer_t *peer)
   return dtls_send_handshake_msg(ctx, peer, DTLS_HT_CERTIFICATE_REQUEST,
 				 buf, p - buf);
 }
+#endif /* DTLS_ECC */
 
 static int
 dtls_send_server_hello_done(dtls_context_t *ctx, dtls_peer_t *peer)
@@ -1928,6 +1968,7 @@ dtls_send_server_hello_msgs(dtls_context_t *ctx, dtls_peer_t *peer)
     return res;
   }
 
+#ifdef DTLS_ECC
   if (is_tls_ecdhe_ecdsa_with_aes_128_ccm_8(peer->handshake_params->cipher)) {
     const dtls_ecdsa_key_t *ecdsa_key;
 
@@ -1960,7 +2001,11 @@ dtls_send_server_hello_msgs(dtls_context_t *ctx, dtls_peer_t *peer)
         return res;
       }
     }
-  } else if (is_tls_psk_with_aes_128_ccm_8(peer->handshake_params->cipher)) {
+  }
+#endif /* DTLS_ECC */
+
+#ifdef DTLS_PSK
+  if (is_tls_psk_with_aes_128_ccm_8(peer->handshake_params->cipher)) {
     const dtls_psk_key_t *psk;
 
     res = CALL(ctx, get_psk_key, &peer->session, NULL, 0, &psk);
@@ -1978,6 +2023,7 @@ dtls_send_server_hello_msgs(dtls_context_t *ctx, dtls_peer_t *peer)
       }
     }
   }
+#endif /* DTLS_PSK */
 
   res = dtls_send_server_hello_done(ctx, peer);
 
@@ -2001,14 +2047,15 @@ dtls_send_client_key_exchange(dtls_context_t *ctx, dtls_peer_t *peer)
 {
   uint8 buf[DTLS_CKXEC_LENGTH];
   uint8 *p;
-  int err;
   dtls_handshake_parameters_t *handshake = peer->handshake_params;
 
   p = buf;
 
   switch (handshake->cipher) {
+#ifdef DTLS_PSK
   case TLS_PSK_WITH_AES_128_CCM_8: {
     const dtls_psk_key_t *psk;
+    int err;
 
     err = CALL(ctx, get_psk_key, &peer->session, handshake->keyx.psk.identity,
 	       handshake->keyx.psk.id_length, &psk);
@@ -2030,6 +2077,8 @@ dtls_send_client_key_exchange(dtls_context_t *ctx, dtls_peer_t *peer)
 
     break;
   }
+#endif /* DTLS_PSK */
+#ifdef DTLS_ECC
   case TLS_ECDHE_ECDSA_WITH_AES_128_CCM_8: {
     uint8 *ephemeral_pub_x;
     uint8 *ephemeral_pub_y;
@@ -2052,6 +2101,7 @@ dtls_send_client_key_exchange(dtls_context_t *ctx, dtls_peer_t *peer)
 
     break;
   }
+#endif /* DTLS_ECC */
   default:
     dtls_crit("cipher not supported\n");
     return dtls_alert_fatal_create(DTLS_ALERT_INTERNAL_ERROR);
@@ -2063,6 +2113,7 @@ dtls_send_client_key_exchange(dtls_context_t *ctx, dtls_peer_t *peer)
 				 buf, p - buf);
 }
 
+#ifdef DTLS_ECC
 static int
 dtls_send_certificate_verify_ecdh(dtls_context_t *ctx, dtls_peer_t *peer,
 				   const dtls_ecdsa_key_t *key)
@@ -2097,6 +2148,7 @@ dtls_send_certificate_verify_ecdh(dtls_context_t *ctx, dtls_peer_t *peer,
   return dtls_send_handshake_msg(ctx, peer, DTLS_HT_CERTIFICATE_VERIFY,
 				 buf, p - buf);
 }
+#endif /* DTLS_ECC */
 
 static int
 dtls_send_finished(dtls_context_t *ctx, dtls_peer_t *peer,
@@ -2372,6 +2424,7 @@ check_server_hello_verify_request(dtls_context_t *ctx,
   return res;
 }
 
+#ifdef DTLS_ECC
 static int
 check_server_certificate(dtls_context_t *ctx, 
 			 dtls_peer_t *peer,
@@ -2504,7 +2557,9 @@ check_server_key_exchange_ecdsa(dtls_context_t *ctx,
   }
   return 0;
 }
+#endif /* DTLS_ECC */
 
+#ifdef DTLS_PSK
 static int
 check_server_key_exchange_psk(dtls_context_t *ctx,
 			      dtls_peer_t *peer,
@@ -2541,6 +2596,7 @@ check_server_key_exchange_psk(dtls_context_t *ctx,
   memcpy(config->keyx.psk.identity, data, len);
   return 0;
 }
+#endif /* DTLS_PSK */
 
 static int
 check_certificate_request(dtls_context_t *ctx, 
@@ -2626,13 +2682,17 @@ check_server_hellodone(dtls_context_t *ctx,
 		      uint8 *data, size_t data_length)
 {
   int res;
+#ifdef DTLS_ECC
   const dtls_ecdsa_key_t *ecdsa_key;
+#endif /* DTLS_ECC */
+
   dtls_handshake_parameters_t *handshake = peer->handshake_params;
 
   /* calculate master key, send CCS */
 
   update_hs_hash(peer, data, data_length);
 
+#ifdef DTLS_ECC
   if (handshake->do_client_auth) {
 
     res = CALL(ctx, get_ecdsa_key, &peer->session, &ecdsa_key);
@@ -2648,6 +2708,7 @@ check_server_hellodone(dtls_context_t *ctx,
       return res;
     }
   }
+#endif /* DTLS_ECC */
 
   /* send ClientKeyExchange */
   res = dtls_send_client_key_exchange(ctx, peer);
@@ -2657,6 +2718,7 @@ check_server_hellodone(dtls_context_t *ctx,
     return res;
   }
 
+#ifdef DTLS_ECC
   if (handshake->do_client_auth) {
 
     res = dtls_send_certificate_verify_ecdh(ctx, peer, ecdsa_key);
@@ -2666,6 +2728,7 @@ check_server_hellodone(dtls_context_t *ctx,
       return res;
     }
   }
+#endif /* DTLS_ECC */
 
   res = calculate_key_block(ctx, handshake, peer,
 			    &peer->session, peer->role);
@@ -2852,6 +2915,7 @@ handle_handshake_msg(dtls_context_t *ctx, dtls_peer_t *peer, session_t *session,
 
     break;
 
+#ifdef DTLS_ECC
   case DTLS_HT_CERTIFICATE:
     dtls_debug("DTLS_HT_CERTIFICATE\n");
 
@@ -2872,24 +2936,28 @@ handle_handshake_msg(dtls_context_t *ctx, dtls_peer_t *peer, session_t *session,
     /* update_hs_hash(peer, data, data_length); */
 
     break;
+#endif /* DTLS_ECC */
 
   case DTLS_HT_SERVER_KEY_EXCHANGE:
 
     dtls_debug("DTLS_HT_SERVER_KEY_EXCHANGE\n");
 
+#ifdef DTLS_ECC
     if (is_tls_ecdhe_ecdsa_with_aes_128_ccm_8(peer->handshake_params->cipher)) {
       if (state != DTLS_STATE_WAIT_SERVERKEYEXCHANGE) {
         return dtls_alert_fatal_create(DTLS_ALERT_UNEXPECTED_MESSAGE);
       }
       err = check_server_key_exchange_ecdsa(ctx, peer, data, data_length);
-    } else if (is_tls_psk_with_aes_128_ccm_8(peer->handshake_params->cipher)) {
+    }
+#endif /* DTLS_ECC */
+#ifdef DTLS_PSK
+    if (is_tls_psk_with_aes_128_ccm_8(peer->handshake_params->cipher)) {
       if (state != DTLS_STATE_WAIT_SERVERHELLODONE) {
         return dtls_alert_fatal_create(DTLS_ALERT_UNEXPECTED_MESSAGE);
       }
       err = check_server_key_exchange_psk(ctx, peer, data, data_length);
-    } else {
-      assert(0);
     }
+#endif /* DTLS_PSK */
 
     if (err < 0) {
       dtls_warn("error in check_server_key_exchange err: %i\n", err);
@@ -2999,6 +3067,7 @@ handle_handshake_msg(dtls_context_t *ctx, dtls_peer_t *peer, session_t *session,
       peer->state = DTLS_STATE_WAIT_CHANGECIPHERSPEC;
     break;
 
+#ifdef DTLS_ECC
   case DTLS_HT_CERTIFICATE_VERIFY:
 
     dtls_debug("DTLS_HT_CERTIFICATE_VERIFY\n");
@@ -3015,6 +3084,7 @@ handle_handshake_msg(dtls_context_t *ctx, dtls_peer_t *peer, session_t *session,
     update_hs_hash(peer, data, data_length);
     peer->state = DTLS_STATE_WAIT_CHANGECIPHERSPEC;
     break;
+#endif /* DTLS_ECC */
 
   case DTLS_HT_CLIENT_HELLO:
     /* At this point, we have a good relationship with this peer. This
diff --git a/dtls.h b/dtls.h
index 3cfb732..e74a80b 100644
--- a/dtls.h
+++ b/dtls.h
@@ -136,6 +136,7 @@ typedef struct {
   int (*event)(struct dtls_context_t *ctx, session_t *session, 
 		dtls_alert_level_t level, unsigned short code);
 
+#ifdef DTLS_PSK
   /**
    * Called during handshake to lookup the key for @p id in @p
    * session. If found, the key must be stored in @p result and 
@@ -158,6 +159,9 @@ typedef struct {
 		     const unsigned char *id, size_t id_len, 
 		     const dtls_psk_key_t **result);
 
+#endif /* DTLS_PSK */
+
+#ifdef DTLS_ECC
   /**
    * Called during handshake to get the server's or client's ecdsa
    * key used to authenticate this server or client in this 
@@ -213,6 +217,7 @@ typedef struct {
 			  const unsigned char *other_pub_x,
 			  const unsigned char *other_pub_y,
 			  size_t key_size);
+#endif /* DTLS_ECC */
 } dtls_handler_t;
 
 /** Holds global information of the DTLS engine. */
diff --git a/global.h b/global.h
index b82bbc5..99685b0 100644
--- a/global.h
+++ b/global.h
@@ -134,7 +134,11 @@ typedef unsigned char uint48[6];
 /** Maximum size of DTLS message.
     When Peers are sending bigger messages this causes problems. Californium
     with ECDSA needs at least 220 */
+#ifdef DTLS_ECC
 #define DTLS_MAX_BUF 200
+#else /* DTLS_ECC */
+#define DTLS_MAX_BUF 100
+#endif /* DTLS_ECC */
 #endif
 
 #ifndef DTLS_DEFAULT_MAX_RETRANSMIT
diff --git a/netq.h b/netq.h
index 6ba095f..6715e25 100644
--- a/netq.h
+++ b/netq.h
@@ -23,7 +23,11 @@
  */
 
 #ifndef NETQ_MAXCNT
-#define NETQ_MAXCNT 4 /**< maximum number of elements in netq structure */
+#ifdef DTLS_ECC
+#define NETQ_MAXCNT 5 /**< maximum number of elements in netq structure */
+#elif defined(DTLS_PSK)
+#define NETQ_MAXCNT 3 /**< maximum number of elements in netq structure */
+#endif
 #endif
 
 /** 
diff --git a/tests/dtls-client.c b/tests/dtls-client.c
index 5e1186d..d130a68 100644
--- a/tests/dtls-client.c
+++ b/tests/dtls-client.c
@@ -53,6 +53,7 @@ static const unsigned char ecdsa_pub_key_y[] = {
 			0xE9, 0x3F, 0x98, 0x72, 0x09, 0xDA, 0xED, 0x0B,
 			0x4F, 0xAB, 0xC3, 0x6F, 0xC7, 0x72, 0xF8, 0x29};
 
+#ifdef DTLS_PSK
 /* This function is the "key store" for tinyDTLS. It is called to
  * retrieve a key for the given identiy within this particular
  * session. */
@@ -71,7 +72,9 @@ get_psk_key(struct dtls_context_t *ctx,
   *result = &psk;
   return 0;
 }
+#endif /* DTLS_PSK */
 
+#ifdef DTLS_ECC
 static int
 get_ecdsa_key(struct dtls_context_t *ctx,
 	      const session_t *session,
@@ -95,6 +98,7 @@ verify_ecdsa_key(struct dtls_context_t *ctx,
 		 size_t key_size) {
   return 0;
 }
+#endif /* DTLS_ECC */
 
 static void
 try_send(struct dtls_context_t *ctx, session_t *dst) {
@@ -231,9 +235,13 @@ static dtls_handler_t cb = {
   .write = send_to_peer,
   .read  = read_from_peer,
   .event = NULL,
+#ifdef DTLS_PSK
   .get_psk_key = get_psk_key,
+#endif /* DTLS_PSK */
+#ifdef DTLS_ECC
   .get_ecdsa_key = get_ecdsa_key,
   .verify_ecdsa_key = verify_ecdsa_key
+#endif /* DTLS_ECC */
 };
 
 #define DTLS_CLIENT_CMD_CLOSE "client:close"
diff --git a/tests/dtls-server.c b/tests/dtls-server.c
index b6a788c..0c76c53 100644
--- a/tests/dtls-server.c
+++ b/tests/dtls-server.c
@@ -46,6 +46,7 @@ handle_sigint(int signum) {
 }
 #endif
 
+#ifdef DTLS_PSK
 /* This function is the "key store" for tinyDTLS. It is called to
  * retrieve a key for the given identiy within this particular
  * session. */
@@ -64,7 +65,9 @@ get_psk_key(struct dtls_context_t *ctx,
   *result = &psk;
   return 0;
 }
+#endif /* DTLS_PSK */
 
+#ifdef DTLS_ECC
 static int
 get_ecdsa_key(struct dtls_context_t *ctx,
 	      const session_t *session,
@@ -88,6 +91,7 @@ verify_ecdsa_key(struct dtls_context_t *ctx,
 		 size_t key_size) {
   return 0;
 }
+#endif /* DTLS_ECC */
 
 #define DTLS_SERVER_CMD_CLOSE "server:close"
 #define DTLS_SERVER_CMD_RENEGOTIATE "server:renegotiate"
@@ -211,9 +215,13 @@ static dtls_handler_t cb = {
   .write = send_to_peer,
   .read  = read_from_peer,
   .event = NULL,
+#ifdef DTLS_PSK
   .get_psk_key = get_psk_key,
+#endif /* DTLS_PSK */
+#ifdef DTLS_ECC
   .get_ecdsa_key = get_ecdsa_key,
   .verify_ecdsa_key = verify_ecdsa_key
+#endif /* DTLS_ECC */
 };
 
 int