diff --git a/programs/ssl/ssl_client2.c b/programs/ssl/ssl_client2.c
index 879a127..27284fc 100644
--- a/programs/ssl/ssl_client2.c
+++ b/programs/ssl/ssl_client2.c
@@ -83,6 +83,7 @@
 #define DFL_MIN_VERSION         -1
 #define DFL_MAX_VERSION         -1
 #define DFL_ARC4                -1
+#define DFL_SHA1                -1
 #define DFL_AUTH_MODE           -1
 #define DFL_MFL_CODE            MBEDTLS_SSL_MAX_FRAG_LEN_NONE
 #define DFL_TRUNC_HMAC          -1
@@ -251,6 +252,7 @@
     USAGE_DHMLEN                                            \
     "\n"                                                    \
     "    arc4=%%d             default: (library default: 0)\n" \
+    "    allow_sha1=%%d       default: 0\n"                             \
     "    min_version=%%s      default: (library default: tls1)\n"       \
     "    max_version=%%s      default: (library default: tls1_2)\n"     \
     "    force_version=%%s    default: \"\" (none)\n"       \
@@ -288,6 +290,7 @@
     int min_version;            /* minimum protocol version accepted        */
     int max_version;            /* maximum protocol version accepted        */
     int arc4;                   /* flag for arc4 suites support             */
+    int allow_sha1;             /* flag for SHA-1 support                   */
     int auth_mode;              /* verify mode for connection               */
     unsigned char mfl_code;     /* code for maximum fragment length         */
     int trunc_hmac;             /* negotiate truncated hmac or not          */
@@ -496,6 +499,7 @@
     opt.min_version         = DFL_MIN_VERSION;
     opt.max_version         = DFL_MAX_VERSION;
     opt.arc4                = DFL_ARC4;
+    opt.allow_sha1          = DFL_SHA1;
     opt.auth_mode           = DFL_AUTH_MODE;
     opt.mfl_code            = DFL_MFL_CODE;
     opt.trunc_hmac          = DFL_TRUNC_HMAC;
@@ -708,6 +712,15 @@
                 default:    goto usage;
             }
         }
+        else if( strcmp( p, "allow_sha1" ) == 0 )
+        {
+            switch( atoi( q ) )
+            {
+                case 0:     opt.allow_sha1 = 0;   break;
+                case 1:     opt.allow_sha1 = 1;    break;
+                default:    goto usage;
+            }
+        }
         else if( strcmp( p, "force_version" ) == 0 )
         {
             if( strcmp( q, "ssl3" ) == 0 )
@@ -1094,9 +1107,12 @@
 #if defined(MBEDTLS_X509_CRT_PARSE_C)
     /* The default algorithms profile disables SHA-1, but our tests still
        rely on it heavily. */
-    crt_profile_for_test.allowed_mds |= MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA1 );
-    mbedtls_ssl_conf_cert_profile( &conf, &crt_profile_for_test );
-    mbedtls_ssl_conf_sig_hashes( &conf, ssl_sig_hashes_for_test );
+    if( opt.allow_sha1 > 0 )
+    {
+        crt_profile_for_test.allowed_mds |= MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA1 );
+        mbedtls_ssl_conf_cert_profile( &conf, &crt_profile_for_test );
+        mbedtls_ssl_conf_sig_hashes( &conf, ssl_sig_hashes_for_test );
+    }
 
     if( opt.debug_level > 0 )
         mbedtls_ssl_conf_verify( &conf, my_verify, NULL );