diff --git a/include/polarssl/config.h b/include/polarssl/config.h
index 0b76f08..b2c8d63 100644
--- a/include/polarssl/config.h
+++ b/include/polarssl/config.h
@@ -1784,6 +1784,11 @@
 #define CTR_DRBG_MAX_REQUEST             1024 /**< Maximum number of requested bytes per call */
 #define CTR_DRBG_MAX_SEED_INPUT           384 /**< Maximum size of (re)seed buffer */
 
+// ECP options
+//
+#define POLARSSL_ECP_MAX_BITS             521 /**< Maximum bit size of groups */
+#define POLARSSL_ECP_WINDOW_SIZE            6 /**< Maximum window size used */
+
 // Entropy options
 //
 #define ENTROPY_MAX_SOURCES                20 /**< Maximum number of sources supported */
diff --git a/include/polarssl/ecp.h b/include/polarssl/ecp.h
index a1a37af..2ab458a 100644
--- a/include/polarssl/ecp.h
+++ b/include/polarssl/ecp.h
@@ -161,13 +161,17 @@
 }
 ecp_keypair;
 
+#if !defined(POLARSSL_CONFIG_OPTIONS)
 /**
  * Maximum size of the groups (that is, of N and P)
  */
-#define POLARSSL_ECP_MAX_BITS     521
+#define POLARSSL_ECP_MAX_BITS     521   /**< Maximum bit size of groups */
+#endif
+
 #define POLARSSL_ECP_MAX_BYTES    ( ( POLARSSL_ECP_MAX_BITS + 7 ) / 8 )
 #define POLARSSL_ECP_MAX_PT_LEN   ( 2 * POLARSSL_ECP_MAX_BYTES + 1 )
 
+#if !defined(POLARSSL_CONFIG_OPTIONS)
 /*
  * Maximum "window" size used for point multiplication.
  * Default: 6.
@@ -178,7 +182,8 @@
  *
  * Reduction in size may reduce speed for big curves.
  */
-#define POLARSSL_ECP_WINDOW_SIZE    6   /**< Maximum window size used. */
+#define POLARSSL_ECP_WINDOW_SIZE    6   /**< Maximum window size used */
+#endif
 
 /*
  * Point formats, from RFC 4492's enum ECPointFormat