diff --git a/library/ecp.c b/library/ecp.c
index 66cf58e..8d0f49a 100644
--- a/library/ecp.c
+++ b/library/ecp.c
@@ -830,7 +830,7 @@
         mbedtls_mpi_free( &pt->Y );
 
         if( grp->id == MBEDTLS_ECP_DP_CURVE25519 )
-            /* Set most significant bit to 0 */
+            /* Set most significant bit to 0 as prescribed in RFC7748 §5 */
             MBEDTLS_MPI_CHK( mbedtls_mpi_set_bit( &pt->X, plen * 8 - 1, 0 ) );
     }
 #endif
diff --git a/tests/suites/test_suite_ecp.data b/tests/suites/test_suite_ecp.data
index ffa526d..87e863d 100644
--- a/tests/suites/test_suite_ecp.data
+++ b/tests/suites/test_suite_ecp.data
@@ -120,18 +120,30 @@
 depends_on:MBEDTLS_ECP_DP_SECP192R1_ENABLED
 ecp_read_binary:MBEDTLS_ECP_DP_SECP192R1:"0448d8082a3a1e3112bc03a8ef2f6d40d0a77a6f8e00cc99336ceed4d7cba482e288669ee1b6415626d6f34d28501e060c":"48d8082a3a1e3112bc03a8ef2f6d40d0a77a6f8e00cc9933":"6ceed4d7cba482e288669ee1b6415626d6f34d28501e060c":"01":0
 
-ECP read binary #7 (Montgomery, OK)
+ECP read binary #7 (Curve25519, OK)
 depends_on:MBEDTLS_ECP_DP_CURVE25519_ENABLED
 ecp_read_binary:MBEDTLS_ECP_DP_CURVE25519:"8520f0098930a754748b7ddcb43ef75a0dbf3a0d26381af4eba4a98eaa9b4e6a":"6a4e9baa8ea9a4ebf41a38260d3abf0d5af73eb4dc7d8b7454a7308909f02085":"0":"1":0
 
-ECP read binary #8 (Montgomery, masked first bit)
+ECP read binary #8 (Curve25519, masked first bit)
 depends_on:MBEDTLS_ECP_DP_CURVE25519_ENABLED
 ecp_read_binary:MBEDTLS_ECP_DP_CURVE25519:"8520f0098930a754748b7ddcb43ef75a0dbf3a0d26381af4eba4a98eaa9b4efa":"7a4e9baa8ea9a4ebf41a38260d3abf0d5af73eb4dc7d8b7454a7308909f02085":"0":"1":0
 
-ECP read binary #9 (Montgomery, invalid length)
+ECP read binary #9 (Curve25519, too short)
 depends_on:MBEDTLS_ECP_DP_CURVE25519_ENABLED
 ecp_read_binary:MBEDTLS_ECP_DP_CURVE25519:"20f0098930a754748b7ddcb43ef75a0dbf3a0d26381af4eba4a98eaa9b4e6a":"6a4e9baa8ea9a4ebf41a38260d3abf0d5af73eb4dc7d8b7454a7308909f020":"0":"1":MBEDTLS_ERR_ECP_BAD_INPUT_DATA
 
+ECP read binary #10 (Curve25519, non-canonical)
+depends_on:MBEDTLS_ECP_DP_CURVE25519_ENABLED
+ecp_read_binary:MBEDTLS_ECP_DP_CURVE25519:"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff7f":"7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff":"0":"1":0
+
+ECP read binary #11 (Curve25519, masked non-canonical)
+depends_on:MBEDTLS_ECP_DP_CURVE25519_ENABLED
+ecp_read_binary:MBEDTLS_ECP_DP_CURVE25519:"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff":"7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff":"0":"1":0
+
+ECP read binary #12 (Curve25519, too long)
+depends_on:MBEDTLS_ECP_DP_CURVE25519_ENABLED
+ecp_read_binary:MBEDTLS_ECP_DP_CURVE25519:"8520f0098930a754748b7ddcb43ef75a0dbf3a0d26381af4eba4a98eaa9b4e6a00":"6a4e9baa8ea9a4ebf41a38260d3abf0d5af73eb4dc7d8b7454a7308909f02085":"0":"1":MBEDTLS_ERR_ECP_BAD_INPUT_DATA
+
 ECP tls read point #1 (zero, invalid length byte)
 depends_on:MBEDTLS_ECP_DP_SECP192R1_ENABLED
 mbedtls_ecp_tls_read_point:MBEDTLS_ECP_DP_SECP192R1:"0200":"01":"01":"00":MBEDTLS_ERR_ECP_BAD_INPUT_DATA