diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index 23b692c..ce661fc 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -476,6 +476,11 @@
     esac
 
     case " $CMD_LINE " in
+        *\ ca_callback=1\ *)
+            requires_config_enabled MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK;;
+    esac
+
+    case " $CMD_LINE " in
         *"programs/ssl/dtls_client "*|\
         *"programs/ssl/ssl_client1 "*)
             requires_config_enabled MBEDTLS_CTR_DRBG_C
@@ -2217,7 +2222,6 @@
             "$P_CLI" \
             0
 
-requires_config_enabled MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK
 run_test    "CA callback on client" \
             "$P_SRV debug_level=3" \
             "$P_CLI ca_callback=1 debug_level=3 " \
@@ -2226,7 +2230,6 @@
             -S "error" \
             -C "error"
 
-requires_config_enabled MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK
 requires_config_enabled MBEDTLS_X509_CRT_PARSE_C
 requires_hash_alg SHA_256
 run_test    "CA callback on server" \
@@ -6279,7 +6282,6 @@
 # Tests for auth_mode, using CA callback, these are duplicated from the authentication tests
 # When updating these tests, modify the matching authentication tests accordingly
 
-requires_config_enabled MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK
 run_test    "Authentication, CA callback: server badcert, client required" \
             "$P_SRV crt_file=$DATA_FILES_PATH/server5-badsign.crt \
              key_file=$DATA_FILES_PATH/server5.key" \
@@ -6291,7 +6293,6 @@
             -c "! mbedtls_ssl_handshake returned" \
             -c "X509 - Certificate verification failed"
 
-requires_config_enabled MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK
 run_test    "Authentication, CA callback: server badcert, client optional" \
             "$P_SRV crt_file=$DATA_FILES_PATH/server5-badsign.crt \
              key_file=$DATA_FILES_PATH/server5.key" \
@@ -6303,7 +6304,6 @@
             -C "! mbedtls_ssl_handshake returned" \
             -C "X509 - Certificate verification failed"
 
-requires_config_enabled MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK
 run_test    "Authentication, CA callback: server badcert, client none" \
             "$P_SRV crt_file=$DATA_FILES_PATH/server5-badsign.crt \
              key_file=$DATA_FILES_PATH/server5.key" \
@@ -6322,7 +6322,6 @@
 # occasion (to be fixed). If that bug's fixed, the test needs to be altered to use a
 # different means to have the server ignoring the client's supported curve list.
 
-requires_config_enabled MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK
 run_test    "Authentication, CA callback: server ECDH p256v1, client required, p256v1 unsupported" \
             "$P_SRV debug_level=1 key_file=$DATA_FILES_PATH/server5.key \
              crt_file=$DATA_FILES_PATH/server5.ku-ka.crt" \
@@ -6333,7 +6332,6 @@
             -c "! Certificate verification flags" \
             -C "bad server certificate (ECDH curve)" # Expect failure at earlier verification stage
 
-requires_config_enabled MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK
 run_test    "Authentication, CA callback: server ECDH p256v1, client optional, p256v1 unsupported" \
             "$P_SRV debug_level=1 key_file=$DATA_FILES_PATH/server5.key \
              crt_file=$DATA_FILES_PATH/server5.ku-ka.crt" \
@@ -6344,7 +6342,6 @@
             -c "! Certificate verification flags"\
             -c "bad server certificate (ECDH curve)" # Expect failure only at ECDH params check
 
-requires_config_enabled MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK
 requires_any_configs_enabled $TLS1_2_KEY_EXCHANGES_WITH_CERT
 run_test    "Authentication, CA callback: client SHA384, server required" \
             "$P_SRV ca_callback=1 debug_level=3 auth_mode=required" \
@@ -6356,7 +6353,6 @@
             -c "Supported Signature Algorithm found: 04 " \
             -c "Supported Signature Algorithm found: 05 "
 
-requires_config_enabled MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK
 requires_any_configs_enabled $TLS1_2_KEY_EXCHANGES_WITH_CERT
 run_test    "Authentication, CA callback: client SHA256, server required" \
             "$P_SRV ca_callback=1 debug_level=3 auth_mode=required" \
@@ -6368,7 +6364,6 @@
             -c "Supported Signature Algorithm found: 04 " \
             -c "Supported Signature Algorithm found: 05 "
 
-requires_config_enabled MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK
 run_test    "Authentication, CA callback: client badcert, server required" \
             "$P_SRV ca_callback=1 debug_level=3 auth_mode=required" \
             "$P_CLI debug_level=3 crt_file=$DATA_FILES_PATH/server5-badsign.crt \
@@ -6390,7 +6385,6 @@
 # detect that its write end of the connection is closed and abort
 # before reading the alert message.
 
-requires_config_enabled MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK
 run_test    "Authentication, CA callback: client cert not trusted, server required" \
             "$P_SRV ca_callback=1 debug_level=3 auth_mode=required" \
             "$P_CLI debug_level=3 crt_file=$DATA_FILES_PATH/server5-selfsigned.crt \
@@ -6408,7 +6402,6 @@
             -s "! mbedtls_ssl_handshake returned" \
             -s "X509 - Certificate verification failed"
 
-requires_config_enabled MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK
 run_test    "Authentication, CA callback: client badcert, server optional" \
             "$P_SRV ca_callback=1 debug_level=3 auth_mode=optional" \
             "$P_CLI debug_level=3 crt_file=$DATA_FILES_PATH/server5-badsign.crt \
@@ -6429,7 +6422,6 @@
 
 requires_config_value_equals "MBEDTLS_X509_MAX_INTERMEDIATE_CA" $MAX_IM_CA
 requires_full_size_output_buffer
-requires_config_enabled MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK
 run_test    "Authentication, CA callback: server max_int chain, client default" \
             "$P_SRV crt_file=$DATA_FILES_PATH/dir-maxpath/c09.pem \
                     key_file=$DATA_FILES_PATH/dir-maxpath/09.key" \
@@ -6440,7 +6432,6 @@
 
 requires_config_value_equals "MBEDTLS_X509_MAX_INTERMEDIATE_CA" $MAX_IM_CA
 requires_full_size_output_buffer
-requires_config_enabled MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK
 run_test    "Authentication, CA callback: server max_int+1 chain, client default" \
             "$P_SRV crt_file=$DATA_FILES_PATH/dir-maxpath/c10.pem \
                     key_file=$DATA_FILES_PATH/dir-maxpath/10.key" \
@@ -6451,7 +6442,6 @@
 
 requires_config_value_equals "MBEDTLS_X509_MAX_INTERMEDIATE_CA" $MAX_IM_CA
 requires_full_size_output_buffer
-requires_config_enabled MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK
 run_test    "Authentication, CA callback: server max_int+1 chain, client optional" \
             "$P_SRV crt_file=$DATA_FILES_PATH/dir-maxpath/c10.pem \
                     key_file=$DATA_FILES_PATH/dir-maxpath/10.key" \
@@ -6463,7 +6453,6 @@
 
 requires_config_value_equals "MBEDTLS_X509_MAX_INTERMEDIATE_CA" $MAX_IM_CA
 requires_full_size_output_buffer
-requires_config_enabled MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK
 run_test    "Authentication, CA callback: client max_int+1 chain, server optional" \
             "$P_SRV ca_callback=1 debug_level=3 ca_file=$DATA_FILES_PATH/dir-maxpath/00.crt auth_mode=optional" \
             "$P_CLI crt_file=$DATA_FILES_PATH/dir-maxpath/c10.pem \
@@ -6474,7 +6463,6 @@
 
 requires_config_value_equals "MBEDTLS_X509_MAX_INTERMEDIATE_CA" $MAX_IM_CA
 requires_full_size_output_buffer
-requires_config_enabled MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK
 run_test    "Authentication, CA callback: client max_int+1 chain, server required" \
             "$P_SRV ca_callback=1 debug_level=3 ca_file=$DATA_FILES_PATH/dir-maxpath/00.crt auth_mode=required" \
             "$P_CLI crt_file=$DATA_FILES_PATH/dir-maxpath/c10.pem \
@@ -6485,7 +6473,6 @@
 
 requires_config_value_equals "MBEDTLS_X509_MAX_INTERMEDIATE_CA" $MAX_IM_CA
 requires_full_size_output_buffer
-requires_config_enabled MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK
 run_test    "Authentication, CA callback: client max_int chain, server required" \
             "$P_SRV ca_callback=1 debug_level=3 ca_file=$DATA_FILES_PATH/dir-maxpath/00.crt auth_mode=required" \
             "$P_CLI crt_file=$DATA_FILES_PATH/dir-maxpath/c09.pem \