diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h
index d0e61c5..79aacf7 100644
--- a/include/mbedtls/config.h
+++ b/include/mbedtls/config.h
@@ -3616,7 +3616,7 @@
 //#define MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT      384 /**< Maximum size of (re)seed buffer */
 
 /* ECP options */
-//#define MBEDTLS_ECP_MAX_BITS             521 /**< Maximum bit size of groups */
+//#define MBEDTLS_ECP_MAX_BITS             521 /**< Maximum bit size of groups. Normally determined automatically from the configured curves. */
 //#define MBEDTLS_ECP_WINDOW_SIZE            6 /**< Maximum window size used */
 //#define MBEDTLS_ECP_FIXED_POINT_OPTIM      1 /**< Enable fixed-point speed-up */
 
diff --git a/include/mbedtls/ecp.h b/include/mbedtls/ecp.h
index a4aa3a3..42630e9 100644
--- a/include/mbedtls/ecp.h
+++ b/include/mbedtls/ecp.h
@@ -285,11 +285,17 @@
 #error "MBEDTLS_ECP_MAX_BITS is smaller than the largest supported curve"
 #endif
 
-#else
+#elif defined(MBEDTLS_ECP_C)
 /**
  * The maximum size of the groups, that is, of \c N and \c P.
  */
-#define MBEDTLS_ECP_MAX_BITS     521   /**< The maximum size of groups, in bits. */
+#define MBEDTLS_ECP_MAX_BITS     MBEDTLS_ECP_MAX_BITS_MIN
+
+#else
+/* MBEDTLS_ECP_MAX_BITS is not relevant without MBEDTLS_ECP_C, but set it
+ * to a nonzero value so that code that unconditionally allocates an array
+ * of a size based on it keeps working if built without ECC support. */
+#define MBEDTLS_ECP_MAX_BITS 1
 #endif
 
 #define MBEDTLS_ECP_MAX_BYTES    ( ( MBEDTLS_ECP_MAX_BITS + 7 ) / 8 )