ECHDE-PSK does not use a certificate

fixes #270
diff --git a/ChangeLog b/ChangeLog
index 1c132ab..928012f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -5,6 +5,9 @@
 Bugfix
    * Fix bug causing some handshakes to fail due to some non-fatal alerts not
      begin properly ignored. Found by mancha and Kasom Koht-arsa, #308
+   * Fix build error with configurations where ECDHE-PSK is the only key
+     exchange. Found and fix provided by Chris Hammond. #270
+
 
 = mbed TLS 1.3.14 released 2015-10-06
 
diff --git a/include/polarssl/ssl_ciphersuites.h b/include/polarssl/ssl_ciphersuites.h
index 1fcf4c7..f0519ca 100644
--- a/include/polarssl/ssl_ciphersuites.h
+++ b/include/polarssl/ssl_ciphersuites.h
@@ -252,7 +252,6 @@
     defined(POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED)    || \
     defined(POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)  || \
     defined(POLARSSL_KEY_EXCHANGE_RSA_PSK_ENABLED)      || \
-    defined(POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED)    || \
     defined(POLARSSL_KEY_EXCHANGE_ECDH_RSA_ENABLED)     || \
     defined(POLARSSL_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
 #define POLARSSL_KEY_EXCHANGE__WITH_CERT__ENABLED