diff --git a/tool/client.cc b/tool/client.cc
index 2c8b5147..005afa85 100644
--- a/tool/client.cc
+++ b/tool/client.cc
@@ -43,6 +43,10 @@ static const struct argument kArguments[] = {
         "An OpenSSL-style cipher suite string that configures the offered "
         "ciphers",
     },
+    {
+        "-curves", kOptionalArgument,
+        "An OpenSSL-style ECDH curves list that configures the offered curves",
+    },
     {
         "-max-version", kOptionalArgument,
         "The maximum acceptable protocol version",
@@ -296,6 +300,12 @@ bool Client(const std::vector<std::string> &args) {
     return false;
   }
 
+  if (args_map.count("-curves") != 0 &&
+      !SSL_CTX_set1_curves_list(ctx.get(), args_map["-curves"].c_str())) {
+    fprintf(stderr, "Failed setting curves list\n");
+    return false;
+  }
+
   uint16_t max_version = TLS1_3_VERSION;
   if (args_map.count("-max-version") != 0 &&
       !VersionFromString(&max_version, args_map["-max-version"])) {
diff --git a/tool/server.cc b/tool/server.cc
index ae039059..70a85e5d 100644
--- a/tool/server.cc
+++ b/tool/server.cc
@@ -34,6 +34,10 @@ static const struct argument kArguments[] = {
         "An OpenSSL-style cipher suite string that configures the offered "
         "ciphers",
     },
+    {
+        "-curves", kOptionalArgument,
+        "An OpenSSL-style ECDH curves list that configures the offered curves",
+    },
     {
         "-max-version", kOptionalArgument,
         "The maximum acceptable protocol version",
@@ -190,6 +194,12 @@ bool Server(const std::vector<std::string> &args) {
     return false;
   }
 
+  if (args_map.count("-curves") != 0 &&
+      !SSL_CTX_set1_curves_list(ctx.get(), args_map["-curves"].c_str())) {
+    fprintf(stderr, "Failed setting curves list\n");
+    return false;
+  }
+
   uint16_t max_version = TLS1_3_VERSION;
   if (args_map.count("-max-version") != 0 &&
       !VersionFromString(&max_version, args_map["-max-version"])) {