diff --git a/ibm_db_sa/base.py b/ibm_db_sa/base.py
index 7ac89fb..a67eeab 100644
--- a/ibm_db_sa/base.py
+++ b/ibm_db_sa/base.py
@@ -1475,6 +1475,13 @@ def denormalize_name(self, name):
 
     @log_entry_exit
     def has_table(self, connection, table_name, schema=None, **kw):
+        if not isinstance(table_name, str) or len(table_name) > 128:
+            logger.debug(
+                f"has_table -> returning False (invalid table_name: "
+                f"type={type(table_name).__name__}, "
+                f"len={len(table_name) if isinstance(table_name, str) else 'N/A'})"
+            )
+            return False
         exists = self._reflector.has_table(connection, table_name, schema=schema, **kw)
         logger.debug(f"Table exists -> {exists}")
         return exists
diff --git a/ibm_db_sa/reflection.py b/ibm_db_sa/reflection.py
index a318557..1824a58 100644
--- a/ibm_db_sa/reflection.py
+++ b/ibm_db_sa/reflection.py
@@ -243,6 +243,8 @@ class DB2Reflector(BaseReflector):
     @log_entry_exit
     def has_table(self, connection, table_name, schema=None, **kw):
         try:
+            if not isinstance(table_name, str) or len(table_name) > 128:
+                return False
             logger.debug(f"Checking table existence -> schema={schema}, table={table_name}")
             current_schema = self.denormalize_name(schema or self.default_schema_name)
             original_table_name = table_name
@@ -903,6 +905,8 @@ class AS400Reflector(BaseReflector):
     @log_entry_exit
     def has_table(self, connection, table_name, schema=None, **kw):
         try:
+            if not isinstance(table_name, str) or len(table_name) > 128:
+                return False
             current_schema = self.denormalize_name(schema or self.default_schema_name)
             table_name = self.denormalize_name(table_name)
             logger.debug(
@@ -1503,6 +1507,8 @@ class OS390Reflector(BaseReflector):
     @log_entry_exit
     def has_table(self, connection, table_name, schema=None, **kw):
         try:
+            if not isinstance(table_name, str) or len(table_name) > 128:
+                return False
             current_schema = self.denormalize_name(schema or self.default_schema_name)
             table_name = self.denormalize_name(table_name)
             logger.debug(