diff --git a/ext/pdo/pdo_stmt.c b/ext/pdo/pdo_stmt.c
index 35f3232c20d..d43a0e443c6 100755
--- a/ext/pdo/pdo_stmt.c
+++ b/ext/pdo/pdo_stmt.c
@@ -168,6 +168,11 @@ static int dispatch_param_event(pdo_stmt_t *stmt, enum pdo_param_event event_typ
 
 iterate:
 	if (ht) {
+		if (zend_hash_num_elements(stmt->bound_param_map) != zend_hash_num_elements(ht)) {
+			php_error_docref(NULL TSRMLS_CC, E_WARNING, "Number of bound paramters %d does not match number of bound values %d", zend_hash_num_elements(stmt->bound_param_map), zend_hash_num_elements(ht));
+			return 0;	
+		}
+
 		zend_hash_internal_pointer_reset(ht);
 		while (SUCCESS == zend_hash_get_current_data(ht, (void**)&param)) {
 			if (!stmt->methods->param_hook(stmt, param, event_type TSRMLS_CC)) {