diff --git a/.woodpecker/test-mem.yml b/.woodpecker/test-mem.yml
index a9ce77b..48896a5 100644
--- a/.woodpecker/test-mem.yml
+++ b/.woodpecker/test-mem.yml
@@ -14,5 +14,7 @@ pipeline:
     pull: true
     commands:
       - make test-mem
+      - make clean
+      - make test-mem CFLAGS='-O3 -Werror -Wall'
     when:
       event: [push, pull_request]
diff --git a/.woodpecker/test.yml b/.woodpecker/test.yml
index 6f636ca..a603923 100644
--- a/.woodpecker/test.yml
+++ b/.woodpecker/test.yml
@@ -11,19 +11,12 @@ branches:
 platform: ${PLATFORM}
 
 pipeline:
-  build:
+  build-and-test:
     image: *image
     pull: true
-    commands:
-      - make
-      - make clean
-      - CFLAGS='-O3' make
-    when:
-      event: [push, pull_request]
-
-  test:
-    image: *image
     commands:
       - make test
+      - make clean
+      - make test CFLAGS='-O3 -Werror -Wall'
     when:
       event: [push, pull_request]
diff --git a/src/heap/vieter_heap_tree.c b/src/heap/vieter_heap_tree.c
index bdfe091..10c5437 100644
--- a/src/heap/vieter_heap_tree.c
+++ b/src/heap/vieter_heap_tree.c
@@ -63,16 +63,7 @@ vieter_heap_node *vieter_heap_tree_merge_same_order(vieter_heap_node *root_a,
 
 vieter_heap_node *vieter_heap_tree_merge(vieter_heap_node *target_tree,
                                          vieter_heap_node *other_tree) {
-  /* vieter_heap_node *other_tree, *target_tree, *out; */
-  vieter_heap_node *out;
-
-  /* if (root_a->order <= root_b->order) { */
-  /*   target_tree = root_a; */
-  /*   other_tree = root_b; */
-  /* } else { */
-  /*   target_tree = root_b; */
-  /*   other_tree = root_a; */
-  /* } */
+  vieter_heap_node *out = target_tree;
 
   vieter_heap_node *next_other_tree, *next_target_tree;
   vieter_heap_node *previous_target_tree = NULL;