diff -r 2dd841e364af -r 64919f63f059 src/hash_map.c
--- a/src/hash_map.c	Tue Apr 18 18:01:41 2023 +0200
+++ b/src/hash_map.c	Tue Apr 18 19:10:45 2023 +0200
@@ -48,6 +48,8 @@
         if (elem != NULL) {
             do {
                 struct cx_hash_map_element_s *next = elem->next;
+                // invoke the destructor
+                cx_invoke_destructor(map, elem->data);
                 // free the key data
                 cxFree(map->allocator, elem->key.data.obj);
                 // free the node
@@ -80,7 +82,7 @@
         void *value
 ) {
     struct cx_hash_map_s *hash_map = (struct cx_hash_map_s *) map;
-    CxAllocator *allocator = map->allocator;
+    CxAllocator const *allocator = map->allocator;
 
     unsigned hash = key.hash;
     if (hash == 0) {
@@ -172,12 +174,14 @@
  * @param map the map
  * @param key the key to look up
  * @param remove flag indicating whether the looked up entry shall be removed
+ * @param destroy flag indicating whether the destructor shall be invoked
  * @return a pointer to the value corresponding to the key or \c NULL
  */
 static void *cx_hash_map_get_remove(
         CxMap *map,
         CxHashKey key,
-        bool remove
+        bool remove,
+        bool destroy
 ) {
     struct cx_hash_map_s *hash_map = (struct cx_hash_map_s *) map;
 
@@ -194,10 +198,14 @@
         if (elm->key.hash == hash && elm->key.len == key.len) {
             if (memcmp(elm->key.data.obj, key.data.obj, key.len) == 0) {
                 void *data = NULL;
-                if (map->store_pointer) {
-                    data = *(void **) elm->data;
-                } else if (!remove) {
-                    data = elm->data;
+                if (destroy) {
+                    cx_invoke_destructor(map, elm->data);
+                } else {
+                    if (map->store_pointer) {
+                        data = *(void **) elm->data;
+                    } else {
+                        data = elm->data;
+                    }
                 }
                 if (remove) {
                     cx_hash_map_unlink(hash_map, slot, prev, elm);
@@ -217,14 +225,15 @@
         CxHashKey key
 ) {
     // we can safely cast, because we know when remove=false, the map stays untouched
-    return cx_hash_map_get_remove((CxMap *) map, key, false);
+    return cx_hash_map_get_remove((CxMap *) map, key, false, false);
 }
 
 static void *cx_hash_map_remove(
         CxMap *map,
-        CxHashKey key
+        CxHashKey key,
+        bool destroy
 ) {
-    return cx_hash_map_get_remove(map, key, true);
+    return cx_hash_map_get_remove(map, key, true, destroy);
 }
 
 static void *cx_hash_map_iter_current_entry(void const *it) {
@@ -280,6 +289,9 @@
             }
         }
 
+        // destroy
+        cx_invoke_destructor((struct cx_map_s *) map, elm->data);
+
         // unlink
         cx_hash_map_unlink(map, iter->slot, prev, elm);