diff --git a/changes/ticket16140 b/changes/ticket16140
new file mode 100644
index 0000000000..00c19f1778
--- /dev/null
+++ b/changes/ticket16140
@@ -0,0 +1,6 @@
+  o Removed features:
+
+    - Tor no longer supports copies of OpenSSL that are missing support for
+      Elliptic Curve Cryptography.  In particular support for at least one of
+      P256 or P224 is now required, with manual configuration needed if only
+      P224 is available.
diff --git a/src/common/tortls.c b/src/common/tortls.c
index ca7b15fcd7..57d5408ca8 100644
--- a/src/common/tortls.c
+++ b/src/common/tortls.c
@@ -49,6 +49,9 @@
 #if OPENSSL_VERSION_NUMBER < OPENSSL_V_SERIES(1,0,0)
 #error "We require OpenSSL >= 1.0.0"
 #endif
+#ifdef OPENSSL_NO_EC
+#error "We require OpenSSL with ECC support"
+#endif
 
 #include <openssl/ssl.h>
 #include <openssl/ssl3.h>
@@ -475,7 +478,6 @@ tor_tls_init(void)
     SSL_load_error_strings();
 
 #if (SIZEOF_VOID_P >= 8 &&                              \
-     !defined(OPENSSL_NO_EC) &&                         \
      OPENSSL_VERSION_NUMBER >= OPENSSL_V_SERIES(1,0,1))
     long version = SSLeay();
 
@@ -1327,7 +1329,6 @@ tor_tls_context_new(crypto_pk_t *identity, unsigned int key_lifetime,
     SSL_CTX_set_tmp_dh(result->ctx, crypto_dh_get_dh_(dh));
     crypto_dh_free(dh);
   }
-#if !defined(OPENSSL_NO_EC)
   if (! is_client) {
     int nid;
     EC_KEY *ec_key;
@@ -1343,9 +1344,6 @@ tor_tls_context_new(crypto_pk_t *identity, unsigned int key_lifetime,
       SSL_CTX_set_tmp_ecdh(result->ctx, ec_key);
     EC_KEY_free(ec_key);
   }
-#else
-  (void)flags;
-#endif
   SSL_CTX_set_verify(result->ctx, SSL_VERIFY_PEER,
                      always_accept_verify_cb);
   /* let us realloc bufs that we're writing from */
@@ -2933,3 +2931,29 @@ tor_tls_init_bufferevent(tor_tls_t *tls, struct bufferevent *bufev_in,
 }
 #endif
 
+/** Check whether the ECC group requested is supported by the current OpenSSL
+ * library instance.  Return 1 if the group is supported, and 0 if not.
+ */
+int
+evaluate_ecgroup_for_tls(const char *ecgroup)
+{
+  EC_KEY *ec_key;
+  int nid;
+  int ret;
+
+  if (!ecgroup)
+    nid = NID_tor_default_ecdhe_group;
+  else if (!strcasecmp(ecgroup, "P256"))
+    nid = NID_X9_62_prime256v1;
+  else if (!strcasecmp(ecgroup, "P224"))
+    nid = NID_secp224r1;
+  else
+    return 0;
+
+  ec_key = EC_KEY_new_by_curve_name(nid);
+  ret = (ec_key != NULL);
+  EC_KEY_free(ec_key);
+
+  return ret;
+}
+
diff --git a/src/common/tortls.h b/src/common/tortls.h
index 083052f4b2..9216e83150 100644
--- a/src/common/tortls.h
+++ b/src/common/tortls.h
@@ -139,5 +139,7 @@ int tor_tls_cert_is_valid(int severity,
                           int check_rsa_1024);
 const char *tor_tls_get_ciphersuite_name(tor_tls_t *tls);
 
+int evaluate_ecgroup_for_tls(const char *ecgroup);
+
 #endif
 
diff --git a/src/or/config.c b/src/or/config.c
index 1c04578893..e4a2d1c5ae 100644
--- a/src/or/config.c
+++ b/src/or/config.c
@@ -2806,6 +2806,9 @@ options_validate(or_options_t *old_options, or_options_t *options,
     COMPLAIN("Unrecognized TLSECGroup: Falling back to the default.");
     tor_free(options->TLSECGroup);
   }
+  if (!evaluate_ecgroup_for_tls(options->TLSECGroup)) {
+    REJECT("Unsupported TLSECGroup.");
+  }
 
   if (options->ExcludeNodes && options->StrictNodes) {
     COMPLAIN("You have asked to exclude certain relays from all positions "
diff --git a/src/test/bench.c b/src/test/bench.c
index a74fc776fa..bc2b1f04d8 100644
--- a/src/test/bench.c
+++ b/src/test/bench.c
@@ -19,11 +19,9 @@ const char tor_git_revision[] = "";
 #include "relay.h"
 #include <openssl/opensslv.h>
 #include <openssl/evp.h>
-#ifndef OPENSSL_NO_EC
 #include <openssl/ec.h>
 #include <openssl/ecdh.h>
 #include <openssl/obj_mac.h>
-#endif
 
 #include "config.h"
 #include "crypto_curve25519.h"
@@ -502,8 +500,6 @@ bench_dh(void)
          "      %f millisec each.\n", NANOCOUNT(start, end, iters)/1e6);
 }
 
-#if !defined(OPENSSL_NO_EC)
-#define HAVE_EC_BENCHMARKS
 static void
 bench_ecdh_impl(int nid, const char *name)
 {
@@ -553,7 +549,6 @@ bench_ecdh_p224(void)
 {
   bench_ecdh_impl(NID_secp224r1, "P-224");
 }
-#endif
 
 typedef void (*bench_fn)(void);
 
@@ -576,10 +571,8 @@ static struct benchmark_t benchmarks[] = {
   ENT(cell_aes),
   ENT(cell_ops),
   ENT(dh),
-#ifdef HAVE_EC_BENCHMARKS
   ENT(ecdh_p256),
   ENT(ecdh_p224),
-#endif
   {NULL,NULL,0}
 };