diff --git a/lib/filterx/expr-generator.c b/lib/filterx/expr-generator.c
index 78f9841d712..6ad401e6663 100644
--- a/lib/filterx/expr-generator.c
+++ b/lib/filterx/expr-generator.c
@@ -32,10 +32,27 @@ filterx_generator_set_fillable(FilterXExpr *s, FilterXExpr *fillable)
   self->fillable = fillable;
 }
 
+static FilterXObject *
+_eval(FilterXExpr *s)
+{
+  FilterXExprGenerator *self = (FilterXExprGenerator *) s;
+
+  FilterXObject *fillable = filterx_expr_eval_typed(self->fillable);
+  if (!fillable)
+    return NULL;
+
+  if (self->eval(self, fillable))
+    return fillable;
+
+  filterx_object_unref(fillable);
+  return NULL;
+}
+
 void
 filterx_generator_init_instance(FilterXExpr *s)
 {
   filterx_expr_init_instance(s);
+  s->eval = _eval;
   s->ignore_falsy_result = TRUE;
 }
 
diff --git a/lib/filterx/expr-generator.h b/lib/filterx/expr-generator.h
index 0630afeb595..3f58ce476fc 100644
--- a/lib/filterx/expr-generator.h
+++ b/lib/filterx/expr-generator.h
@@ -31,6 +31,7 @@ struct FilterXExprGenerator_
 {
   FilterXExpr super;
   FilterXExpr *fillable;
+  gboolean (*eval)(FilterXExprGenerator *self, FilterXObject *fillable);
   FilterXObject *(*create_container)(FilterXExprGenerator *self, FilterXExpr *fillable_parent);
 };
 
diff --git a/lib/filterx/expr-literal-generator.c b/lib/filterx/expr-literal-generator.c
index c649fdfbc46..48d9e7cb961 100644
--- a/lib/filterx/expr-literal-generator.c
+++ b/lib/filterx/expr-literal-generator.c
@@ -133,19 +133,12 @@ _list_generator_create_container(FilterXExprGenerator *s, FilterXExpr *fillable_
   return result;
 }
 
-static FilterXObject *
-_literal_generator_eval(FilterXExpr *s)
+static gboolean
+_literal_generator_eval(FilterXExprGenerator *s, FilterXObject *fillable)
 {
   FilterXExprLiteralGenerator *self = (FilterXExprLiteralGenerator *) s;
 
-  FilterXObject *fillable = filterx_expr_eval_typed(self->super.fillable);
-  if (!fillable)
-    return NULL;
-
-  if (!_eval_elements(fillable, self->elements))
-    return NULL;
-
-  return fillable;
+  return _eval_elements(fillable, self->elements);
 }
 
 void
@@ -161,7 +154,7 @@ static void
 _literal_generator_init_instance(FilterXExprLiteralGenerator *self)
 {
   filterx_generator_init_instance(&self->super.super);
-  self->super.super.eval = _literal_generator_eval;
+  self->super.eval = _literal_generator_eval;
   self->super.super.free_fn = _literal_generator_free;
 }
 
diff --git a/lib/filterx/expr-regexp.c b/lib/filterx/expr-regexp.c
index a5628952d29..99b106e215a 100644
--- a/lib/filterx/expr-regexp.c
+++ b/lib/filterx/expr-regexp.c
@@ -336,36 +336,30 @@ typedef struct FilterXExprRegexpSearchGenerator_
   pcre2_code_8 *pattern;
 } FilterXExprRegexpSearchGenerator;
 
-static FilterXObject *
-_regexp_search_generator_eval(FilterXExpr *s)
+static gboolean
+_regexp_search_generator_eval(FilterXExprGenerator *s, FilterXObject *fillable)
 {
   FilterXExprRegexpSearchGenerator *self = (FilterXExprRegexpSearchGenerator *) s;
 
-  FilterXObject *fillable = filterx_expr_eval_typed(self->super.fillable);
-  if (!fillable)
-    return NULL;
-
-  FilterXObject *result = NULL;
+  gboolean result;
   FilterXReMatchState state;
   _state_init(&state);
 
   gboolean matched = _match(self->lhs, self->pattern, &state);
-  if (!state.match_data)
+  if (!matched)
     {
-      /* Error happened during matching. */
+      result = TRUE;
       goto exit;
     }
 
-  if (matched)
+  if (!state.match_data)
     {
-      if (!_store_matches(self->pattern, &state, fillable))
-        {
-          filterx_object_unref(fillable);
-          goto exit;
-        }
+      /* Error happened during matching. */
+      result = FALSE;
+      goto exit;
     }
 
-  result = fillable;
+  result = _store_matches(self->pattern, &state, fillable);
 
 exit:
   _state_cleanup(&state);
@@ -409,7 +403,7 @@ filterx_expr_regexp_search_generator_new(FilterXExpr *lhs, const gchar *pattern)
   FilterXExprRegexpSearchGenerator *self = g_new0(FilterXExprRegexpSearchGenerator, 1);
 
   filterx_generator_init_instance(&self->super.super);
-  self->super.super.eval = _regexp_search_generator_eval;
+  self->super.eval = _regexp_search_generator_eval;
   self->super.super.free_fn = _regexp_search_generator_free;
   self->super.create_container = _regexp_search_generator_create_container;