diff --git a/src/include/taler_exchange_service.h b/src/include/taler_exchange_service.h
index 938b74457..b2d0bf710 100644
--- a/src/include/taler_exchange_service.h
+++ b/src/include/taler_exchange_service.h
@@ -3600,8 +3600,7 @@ struct TALER_EXCHANGE_KycProofHandle;
  * @param h_payto hash of payto URI identifying the target account
  * @param logic name of the KYC logic to run
  * @param args additional args to pass, can be NULL
- *        or a string to append to the URL. Must
- *        then begin with '/' or '?'.
+ *        or a string to append to the URL. Must then begin with '&'.
  * @param cb function to call with the result
  * @param cb_cls closure for @a cb
  * @return NULL on error
diff --git a/src/include/taler_testing_lib.h b/src/include/taler_testing_lib.h
index 0418ab17e..846be4183 100644
--- a/src/include/taler_testing_lib.h
+++ b/src/include/taler_testing_lib.h
@@ -2535,7 +2535,6 @@ TALER_TESTING_cmd_check_kyc_get (const char *label,
  * @param logic_section name of the KYC provider section
  *         in the exchange configuration for this proof
  * @param code OAuth 2.0 code to use
- * @param state OAuth 2.0 state to use
  * @param expected_response_code expected HTTP status
  * @return the command
  */
@@ -2545,7 +2544,6 @@ TALER_TESTING_cmd_proof_kyc_oauth2 (
   const char *payment_target_reference,
   const char *logic_section,
   const char *code,
-  const char *state,
   unsigned int expected_response_code);
 
 
diff --git a/src/lib/exchange_api_kyc_proof.c b/src/lib/exchange_api_kyc_proof.c
index 0436e1c52..1298df4fd 100644
--- a/src/lib/exchange_api_kyc_proof.c
+++ b/src/lib/exchange_api_kyc_proof.c
@@ -154,8 +154,7 @@ TALER_EXCHANGE_kyc_proof (struct TALER_EXCHANGE_Handle *exchange,
   if (NULL == args)
     args = "";
   else
-    GNUNET_assert ( (args[0] == '?') ||
-                    (args[0] == '/') );
+    GNUNET_assert (args[0] == '&');
   if (GNUNET_YES !=
       TEAH_handle_is_ready (exchange))
   {
@@ -172,9 +171,9 @@ TALER_EXCHANGE_kyc_proof (struct TALER_EXCHANGE_Handle *exchange,
                                          sizeof (hstr));
     *end = '\0';
     GNUNET_asprintf (&arg_str,
-                     "/kyc-proof/%s/%s%s",
-                     hstr,
+                     "/kyc-proof/%s?state=%s%s",
                      logic,
+                     hstr,
                      args);
   }
   kph = GNUNET_new (struct TALER_EXCHANGE_KycProofHandle);
diff --git a/src/testing/test_kyc_api.c b/src/testing/test_kyc_api.c
index 8ab4cffc8..dc302f3a4 100644
--- a/src/testing/test_kyc_api.c
+++ b/src/testing/test_kyc_api.c
@@ -131,7 +131,6 @@ run (void *cls,
                                         "withdraw-coin-1-lacking-kyc",
                                         "kyc-provider-test-oauth2",
                                         "pass",
-                                        "state",
                                         MHD_HTTP_SEE_OTHER),
     TALER_TESTING_cmd_withdraw_amount ("withdraw-coin-1-with-kyc",
                                        "create-reserve-1",
@@ -175,7 +174,6 @@ run (void *cls,
                                         "track-deposit-kyc-ready",
                                         "kyc-provider-test-oauth2",
                                         "bad",
-                                        "state",
                                         MHD_HTTP_BAD_GATEWAY),
     TALER_TESTING_cmd_oauth ("start-oauth-service",
                              6666),
@@ -183,13 +181,11 @@ run (void *cls,
                                         "track-deposit-kyc-ready",
                                         "kyc-provider-test-oauth2",
                                         "bad",
-                                        "state",
                                         MHD_HTTP_FORBIDDEN),
     TALER_TESTING_cmd_proof_kyc_oauth2 ("proof-kyc-fail",
                                         "track-deposit-kyc-ready",
                                         "kyc-provider-test-oauth2",
                                         "pass",
-                                        "state",
                                         MHD_HTTP_SEE_OTHER),
     CMD_EXEC_AGGREGATOR ("run-aggregator-after-kyc"),
     TALER_TESTING_cmd_check_bank_transfer (
@@ -216,7 +212,6 @@ run (void *cls,
                                         "wallet-kyc-fail",
                                         "kyc-provider-test-oauth2",
                                         "pass",
-                                        "state",
                                         MHD_HTTP_SEE_OTHER),
     TALER_TESTING_cmd_check_kyc_get ("wallet-kyc-check",
                                      "wallet-kyc-fail",
@@ -311,7 +306,6 @@ run (void *cls,
                                         "purse-merge-into-reserve",
                                         "kyc-provider-test-oauth2",
                                         "pass",
-                                        "state",
                                         MHD_HTTP_SEE_OTHER),
     TALER_TESTING_cmd_purse_merge (
       "purse-merge-into-reserve",
@@ -353,7 +347,6 @@ run (void *cls,
                                         "purse-create-with-reserve",
                                         "kyc-provider-test-oauth2",
                                         "pass",
-                                        "state",
                                         MHD_HTTP_SEE_OTHER),
     TALER_TESTING_cmd_purse_create_with_reserve (
       "purse-create-with-reserve",
diff --git a/src/testing/testing_api_cmd_kyc_proof.c b/src/testing/testing_api_cmd_kyc_proof.c
index ed0df5564..ff76e415c 100644
--- a/src/testing/testing_api_cmd_kyc_proof.c
+++ b/src/testing/testing_api_cmd_kyc_proof.c
@@ -43,11 +43,6 @@ struct KycProofGetState
    */
   const char *code;
 
-  /**
-   * State to pass.
-   */
-  const char *state;
-
   /**
    * Logic section name to pass to `/kyc-proof/` handler.
    */
@@ -158,10 +153,12 @@ proof_kyc_run (void *cls,
     TALER_TESTING_interpreter_fail (kps->is);
     return;
   }
-  GNUNET_asprintf (&uargs,
-                   "?code=%s&state=%s",
-                   kps->code,
-                   kps->state);
+  if (NULL == kps->code)
+    uargs = NULL;
+  else
+    GNUNET_asprintf (&uargs,
+                     "&code=%s",
+                     kps->code);
   kps->kph = TALER_EXCHANGE_kyc_proof (is->exchange,
                                        h_payto,
                                        kps->logic,
@@ -235,14 +232,12 @@ TALER_TESTING_cmd_proof_kyc_oauth2 (
   const char *payment_target_reference,
   const char *logic_section,
   const char *code,
-  const char *state,
   unsigned int expected_response_code)
 {
   struct KycProofGetState *kps;
 
   kps = GNUNET_new (struct KycProofGetState);
   kps->code = code;
-  kps->state = state;
   kps->logic = logic_section;
   kps->payment_target_reference = payment_target_reference;
   kps->expected_response_code = expected_response_code;