diff --git a/src/coherency.c b/src/coherency.c
index d8406da1..41986ac1 100644
--- a/src/coherency.c
+++ b/src/coherency.c
@@ -162,8 +162,8 @@ __hot int coherency_check_head(MDBX_txn *txn, const meta_ptr_t head,
     if ((txn->dbs[FREE_DBI].flags & DB_PERSISTENT_FLAGS) != MDBX_INTEGERKEY ||
         unaligned_peek_u64(4, &head.ptr_c->magic_and_version) ==
             MDBX_DATA_MAGIC) {
-      ERROR("unexpected/invalid db-flags 0x%u for GC/FreeDB",
-            txn->dbs[FREE_DBI].flags);
+      ERROR("unexpected/invalid db-flags 0x%x for %s", txn->dbs[FREE_DBI].flags,
+            "GC/FreeDB");
       return MDBX_INCOMPATIBLE;
     }
     txn->dbs[FREE_DBI].flags &= DB_PERSISTENT_FLAGS;
diff --git a/src/dxb.c b/src/dxb.c
index f9a62d36..e15e0832 100644
--- a/src/dxb.c
+++ b/src/dxb.c
@@ -628,8 +628,8 @@ __cold int dxb_setup(MDBX_env *env, const int lck_rc,
 
   if (unlikely((header.trees.gc.flags & DB_PERSISTENT_FLAGS) !=
                MDBX_INTEGERKEY)) {
-    ERROR("unexpected/invalid db-flags 0x%u for GC/FreeDB",
-          header.trees.gc.flags);
+    ERROR("unexpected/invalid db-flags 0x%x for %s", header.trees.gc.flags,
+          "GC/FreeDB");
     return MDBX_INCOMPATIBLE;
   }
   env->dbs_flags[FREE_DBI] = DB_VALID | MDBX_INTEGERKEY;
diff --git a/src/meta.c b/src/meta.c
index 3711c747..3f2bfcd6 100644
--- a/src/meta.c
+++ b/src/meta.c
@@ -544,13 +544,13 @@ __cold int meta_validate(MDBX_env *env, meta_t *const meta,
   if (unlikely(meta->trees.gc.flags != MDBX_INTEGERKEY) &&
       ((meta->trees.gc.flags & DB_PERSISTENT_FLAGS) != MDBX_INTEGERKEY ||
        magic_and_version == MDBX_DATA_MAGIC)) {
-    WARNING("meta[%u] has invalid %s flags 0x%u, skip it", meta_number,
+    WARNING("meta[%u] has invalid %s flags 0x%x, skip it", meta_number,
             "GC/FreeDB", meta->trees.gc.flags);
     return MDBX_INCOMPATIBLE;
   }
 
   if (unlikely(!check_sdb_flags(meta->trees.main.flags))) {
-    WARNING("meta[%u] has invalid %s flags 0x%u, skip it", meta_number,
+    WARNING("meta[%u] has invalid %s flags 0x%x, skip it", meta_number,
             "MainDB", meta->trees.main.flags);
     return MDBX_INCOMPATIBLE;
   }
diff --git a/src/txn.c b/src/txn.c
index 59c661f1..276692bc 100644
--- a/src/txn.c
+++ b/src/txn.c
@@ -1222,8 +1222,8 @@ int txn_renew(MDBX_txn *txn, unsigned flags) {
   }
 
   if (unlikely(txn->dbs[FREE_DBI].flags != MDBX_INTEGERKEY)) {
-    ERROR("unexpected/invalid db-flags 0x%u for GC/FreeDB",
-          txn->dbs[FREE_DBI].flags);
+    ERROR("unexpected/invalid db-flags 0x%x for %s", txn->dbs[FREE_DBI].flags,
+          "GC/FreeDB");
     rc = MDBX_INCOMPATIBLE;
     goto bailout;
   }