diff --git a/ChangeLog.d/ecp_max_bits.txt b/ChangeLog.d/ecp_max_bits.txt
index bfbe11f..834deda 100644
--- a/ChangeLog.d/ecp_max_bits.txt
+++ b/ChangeLog.d/ecp_max_bits.txt
@@ -2,3 +2,7 @@
    * It was possible to configure MBEDTLS_ECP_MAX_BITS to a value that is
      too small, leading to buffer overflows in ECC operations. Fail the build
      in such a case.
+
+Features
+   * MBEDTLS_ECP_MAX_BITS is now determined automatically from the configured
+     curves and no longer needs to be configured explicitly to save RAM.
diff --git a/configs/config-suite-b.h b/configs/config-suite-b.h
index 6eb03a9..9cad382 100644
--- a/configs/config-suite-b.h
+++ b/configs/config-suite-b.h
@@ -80,8 +80,7 @@
 #define MBEDTLS_AES_ROM_TABLES
 
 /* Save RAM by adjusting to our exact needs */
-#define MBEDTLS_ECP_MAX_BITS   384
-#define MBEDTLS_MPI_MAX_SIZE    48 // 384 bits is 48 bytes
+#define MBEDTLS_MPI_MAX_SIZE    48 // 48 bytes for a 384-bit elliptic curve
 
 /* Save RAM at the expense of speed, see ecp.h */
 #define MBEDTLS_ECP_WINDOW_SIZE        2
diff --git a/configs/config-thread.h b/configs/config-thread.h
index 47dd5e2..8464fcb 100644
--- a/configs/config-thread.h
+++ b/configs/config-thread.h
@@ -81,8 +81,7 @@
 #define MBEDTLS_AES_ROM_TABLES
 
 /* Save RAM by adjusting to our exact needs */
-#define MBEDTLS_ECP_MAX_BITS             256
-#define MBEDTLS_MPI_MAX_SIZE              32 // 256 bits is 32 bytes
+#define MBEDTLS_MPI_MAX_SIZE              32 // 32 bytes for a 256-bit elliptic curve
 
 /* Save ROM and a few bytes of RAM by specifying our own ciphersuite list */
 #define MBEDTLS_SSL_CIPHERSUITES MBEDTLS_TLS_ECJPAKE_WITH_AES_128_CCM_8
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 )