diff --git a/lib/filterx/filterx-metrics.c b/lib/filterx/filterx-metrics.c
index 7622793e2..65b376c88 100644
--- a/lib/filterx/filterx-metrics.c
+++ b/lib/filterx/filterx-metrics.c
@@ -33,7 +33,6 @@
 #include "stats/stats-registry.h"
 #include "metrics/dyn-metrics-cache.h"
 #include "scratch-buffers.h"
-#include "atomic.h"
 
 struct _FilterXMetrics
 {
@@ -46,7 +45,6 @@ struct _FilterXMetrics
   FilterXMetricsLabels *labels;
   gint level;
 
-  GAtomicCounter is_optimized;
   StatsCluster *const_cluster;
 };
 
@@ -110,9 +108,6 @@ _optimize(FilterXMetrics *self)
 {
   stats_lock();
 
-  if (g_atomic_counter_get(&self->is_optimized))
-    goto exit;
-
   if (!self->key.str || !filterx_metrics_labels_is_const(self->labels))
     goto exit;
 
@@ -136,7 +131,6 @@ _optimize(FilterXMetrics *self)
   self->key.str = NULL;
 
 exit:
-  g_atomic_counter_set(&self->is_optimized, TRUE);
   stats_unlock();
 }
 
@@ -149,13 +143,6 @@ filterx_metrics_get_stats_counter(FilterXMetrics *self, StatsCounterItem **count
       return TRUE;
     }
 
-  /*
-   * We need to delay the optimization to the first get() call,
-   * as we don't have stats options when FilterXExprs are being created.
-   */
-  if (!g_atomic_counter_get(&self->is_optimized))
-    _optimize(self);
-
   if (_is_const(self))
     {
       *counter = stats_cluster_single_get_counter(self->const_cluster);
@@ -191,6 +178,8 @@ filterx_metrics_init(FilterXMetrics *self, GlobalConfig *cfg)
       return FALSE;
     }
 
+  _optimize(self);
+
   return TRUE;
 }
 
@@ -265,8 +254,6 @@ filterx_metrics_new(gint level, FilterXExpr *key, FilterXExpr *labels)
   if (!_init_labels(self, labels))
     goto error;
 
-  g_atomic_counter_set(&self->is_optimized, FALSE);
-
   return self;
 
 error:
diff --git a/modules/metrics-probe/tests/test_filterx_func_update_metric.c b/modules/metrics-probe/tests/test_filterx_func_update_metric.c
index 3d8525ad8..f0f538a43 100644
--- a/modules/metrics-probe/tests/test_filterx_func_update_metric.c
+++ b/modules/metrics-probe/tests/test_filterx_func_update_metric.c
@@ -95,6 +95,7 @@ Test(filterx_func_update_metric, key_and_labels)
   _add_label(labels, "test_label_1", "foo");
   _add_label(labels, "test_label_2", "bar");
   FilterXExpr *func = _create_func(key, labels, NULL, NULL);
+  cr_assert(filterx_expr_init(func, configuration));
 
   StatsClusterLabel expected_labels[] =
   {
@@ -115,6 +116,7 @@ Test(filterx_func_update_metric, key_and_labels)
                                           G_N_ELEMENTS(expected_labels),
                                           2);
 
+  filterx_expr_deinit(func, configuration);
   filterx_expr_unref(func);
 }
 
@@ -122,6 +124,7 @@ Test(filterx_func_update_metric, increment)
 {
   FilterXExpr *key = filterx_literal_new(filterx_string_new("test_key", -1));
   FilterXExpr *func = _create_func(key, NULL, filterx_non_literal_new(filterx_integer_new(42)), NULL);
+  cr_assert(filterx_expr_init(func, configuration));
 
   StatsClusterLabel expected_labels[] = {};
 
@@ -137,6 +140,7 @@ Test(filterx_func_update_metric, increment)
                                           G_N_ELEMENTS(expected_labels),
                                           84);
 
+  filterx_expr_deinit(func, configuration);
   filterx_expr_unref(func);
 }
 
@@ -149,7 +153,9 @@ Test(filterx_func_update_metric, level)
   cr_assert(cfg_init(configuration));
   func = _create_func(filterx_literal_new(filterx_string_new("test_key", -1)), NULL, NULL,
                       filterx_literal_new(filterx_integer_new(2)));
+  cr_assert(filterx_expr_init(func, configuration));
   cr_assert(_eval(func));
+  filterx_expr_deinit(func, configuration);
   filterx_expr_unref(func);
   cr_assert_not(metrics_probe_test_stats_cluster_exists("test_key", expected_labels, G_N_ELEMENTS(expected_labels)));
   cr_assert(cfg_deinit(configuration));
@@ -158,7 +164,9 @@ Test(filterx_func_update_metric, level)
   cr_assert(cfg_init(configuration));
   func = _create_func(filterx_literal_new(filterx_string_new("test_key", -1)), NULL, NULL,
                       filterx_literal_new(filterx_integer_new(2)));
+  cr_assert(filterx_expr_init(func, configuration));
   cr_assert(_eval(func));
+  filterx_expr_deinit(func, configuration);
   filterx_expr_unref(func);
   cr_assert_not(metrics_probe_test_stats_cluster_exists("test_key", expected_labels, G_N_ELEMENTS(expected_labels)));
   cr_assert(cfg_deinit(configuration));
@@ -167,7 +175,9 @@ Test(filterx_func_update_metric, level)
   cr_assert(cfg_init(configuration));
   func = _create_func(filterx_literal_new(filterx_string_new("test_key", -1)), NULL, NULL,
                       filterx_literal_new(filterx_integer_new(2)));
+  cr_assert(filterx_expr_init(func, configuration));
   cr_assert(_eval(func));
+  filterx_expr_deinit(func, configuration);
   filterx_expr_unref(func);
   metrics_probe_test_assert_counter_value("test_key",
                                           expected_labels,