diff --git a/programs/ssl/ssl_client2.c b/programs/ssl/ssl_client2.c
index 1ddfb80..7979e39 100644
--- a/programs/ssl/ssl_client2.c
+++ b/programs/ssl/ssl_client2.c
@@ -987,6 +987,7 @@
 
     return( mbedtls_net_send( io_ctx->net, buf, len ) );
 }
+#include "ssl_test_common_source.c"
 
 #if defined(MBEDTLS_X509_CRT_PARSE_C)
 static unsigned char peer_crt_info[1024];
diff --git a/programs/ssl/ssl_server2.c b/programs/ssl/ssl_server2.c
index 4e11cb3..a1fbca6 100644
--- a/programs/ssl/ssl_server2.c
+++ b/programs/ssl/ssl_server2.c
@@ -1088,6 +1088,7 @@
 
     return( mbedtls_net_send( io_ctx->net, buf, len ) );
 }
+#include "ssl_test_common_source.c"
 
 /*
  * Return authmode from string, or -1 on error
diff --git a/programs/ssl/ssl_test_common_source.c b/programs/ssl/ssl_test_common_source.c
new file mode 100644
index 0000000..78b9331
--- /dev/null
+++ b/programs/ssl/ssl_test_common_source.c
@@ -0,0 +1,25 @@
+/*
+ *  Common source code for SSL test programs. This file is included by
+ *  both ssl_client2.c and ssl_server2.c and is intended for source
+ *  code that is textually identical in both programs, but that cannot be
+ *  compiled separately because it refers to types or macros that are
+ *  different in the two programs, or because it would have an incomplete
+ *  type.
+ *
+ *  This file is meant to be #include'd and cannot be compiled separately.
+ *
+ *  Copyright The Mbed TLS Contributors
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *  not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
diff --git a/programs/ssl/ssl_test_lib.c b/programs/ssl/ssl_test_lib.c
index e3645f3..897afc6 100644
--- a/programs/ssl/ssl_test_lib.c
+++ b/programs/ssl/ssl_test_lib.c
@@ -1,5 +1,8 @@
 /*
- *  Common code for SSL test programs
+ *  Common code library for SSL test programs.
+ *
+ *  In addition to the functions in this file, there is shared source code
+ *  that cannot be compiled separately in "ssl_test_common_source.c".
  *
  *  Copyright The Mbed TLS Contributors
  *  SPDX-License-Identifier: Apache-2.0