diff --git a/test/cases.cc b/test/cases.cc
index 98255f52..9730b10c 100644
--- a/test/cases.cc
+++ b/test/cases.cc
@@ -15,7 +15,15 @@
 #include "test.h"
 
 void configure_actor(unsigned &last_space_id, const actor_testcase testcase,
-                     const char *space_id_cstr, const actor_params &params) {
+                     const char *space_id_cstr, actor_params params) {
+  // silently fix key/data length for fixed-length modes
+  if ((params.table_flags & MDBX_INTEGERKEY) &&
+      params.keylen_min != params.keylen_max)
+    params.keylen_min = params.keylen_max;
+  if ((params.table_flags & (MDBX_INTEGERDUP | MDBX_DUPFIXED)) &&
+      params.datalen_min != params.datalen_max)
+    params.datalen_min = params.datalen_max;
+
   unsigned wait4id = 0;
   if (params.waitfor_nops) {
     for (auto i = global::actors.rbegin(); i != global::actors.rend(); ++i) {
@@ -56,7 +64,7 @@ void configure_actor(unsigned &last_space_id, const actor_testcase testcase,
   global::databases.insert(params.pathname_db);
 }
 
-void testcase_setup(const char *casename, actor_params &params,
+void testcase_setup(const char *casename, const actor_params &params,
                     unsigned &last_space_id) {
   if (strcmp(casename, "basic") == 0) {
     log_notice(">>> testcase_setup(%s)", casename);
diff --git a/test/main.cc b/test/main.cc
index 5d50b043..28d8d261 100644
--- a/test/main.cc
+++ b/test/main.cc
@@ -270,6 +270,27 @@ int main(int argc, char *const argv[]) {
       if ((params.table_flags & MDBX_DUPSORT) == 0)
         params.table_flags &=
             ~(MDBX_DUPFIXED | MDBX_REVERSEDUP | MDBX_INTEGERDUP);
+      const unsigned keylen_max = params.mdbx_keylen_max();
+      if (params.keylen_min > keylen_max)
+        params.keylen_min = keylen_max;
+      if (params.keylen_max > keylen_max)
+        params.keylen_max = keylen_max;
+      const unsigned keylen_min = params.mdbx_keylen_min();
+      if (params.keylen_min < keylen_min)
+        params.keylen_min = keylen_min;
+      if (params.keylen_max < keylen_min)
+        params.keylen_max = keylen_min;
+
+      const unsigned datalen_max = params.mdbx_datalen_max();
+      if (params.datalen_min > datalen_max)
+        params.datalen_min = datalen_max;
+      if (params.datalen_max > datalen_max)
+        params.datalen_max = datalen_max;
+      const unsigned datalen_min = params.mdbx_datalen_min();
+      if (params.datalen_min < datalen_min)
+        params.datalen_min = datalen_min;
+      if (params.datalen_max < datalen_min)
+        params.datalen_max = datalen_min;
       continue;
     }
 
@@ -371,7 +392,7 @@ int main(int argc, char *const argv[]) {
                              params.datalen_min, config::no_scale,
                              params.mdbx_datalen_min(),
                              params.mdbx_datalen_max())) {
-      if ((params.table_flags & MDBX_DUPFIXED) ||
+      if ((params.table_flags & (MDBX_INTEGERDUP | MDBX_DUPFIXED)) ||
           params.datalen_max < params.datalen_min)
         params.datalen_max = params.datalen_min;
       continue;
@@ -380,7 +401,7 @@ int main(int argc, char *const argv[]) {
                              params.datalen_max, config::no_scale,
                              params.mdbx_datalen_min(),
                              params.mdbx_datalen_max())) {
-      if ((params.table_flags & MDBX_DUPFIXED) ||
+      if ((params.table_flags & (MDBX_INTEGERDUP | MDBX_DUPFIXED)) ||
           params.datalen_min > params.datalen_max)
         params.datalen_min = params.datalen_max;
       continue;
diff --git a/test/test.h b/test/test.h
index acd9f520..1a765143 100644
--- a/test/test.h
+++ b/test/test.h
@@ -42,10 +42,10 @@
 
 bool test_execute(const actor_config &config);
 std::string thunk_param(const actor_config &config);
-void testcase_setup(const char *casename, actor_params &params,
+void testcase_setup(const char *casename, const actor_params &params,
                     unsigned &last_space_id);
 void configure_actor(unsigned &last_space_id, const actor_testcase testcase,
-                     const char *space_id_cstr, const actor_params &params);
+                     const char *space_id_cstr, actor_params params);
 void keycase_setup(const char *casename, actor_params &params);
 
 namespace global {