diff -r 5d0244c6fa3e -r 2c2304622981 src/hash_map.c
--- a/src/hash_map.c	Thu Apr 20 19:13:25 2023 +0200
+++ b/src/hash_map.c	Fri Apr 21 18:38:18 2023 +0200
@@ -51,7 +51,7 @@
                 // invoke the destructor
                 cx_invoke_destructor(map, elem->data);
                 // free the key data
-                cxFree(map->allocator, elem->key.data.obj);
+                cxFree(map->allocator, (void *) elem->key.data);
                 // free the node
                 cxFree(map->allocator, elem);
                 // proceed
@@ -100,7 +100,7 @@
     }
 
     if (elm != NULL && elm->key.hash == hash && elm->key.len == key.len &&
-        memcmp(elm->key.data.obj, key.data.obj, key.len) == 0) {
+        memcmp(elm->key.data, key.data, key.len) == 0) {
         // overwrite existing element
         if (map->store_pointer) {
             memcpy(elm->data, &value, sizeof(void *));
@@ -129,8 +129,8 @@
         if (kd == NULL) {
             return -1;
         }
-        memcpy(kd, key.data.obj, key.len);
-        e->key.data.obj = kd;
+        memcpy(kd, key.data, key.len);
+        e->key.data = kd;
         e->key.len = key.len;
         e->key.hash = hash;
 
@@ -162,7 +162,7 @@
         prev->next = elm->next;
     }
     // free element
-    cxFree(hash_map->base.allocator, elm->key.data.obj);
+    cxFree(hash_map->base.allocator, (void *) elm->key.data);
     cxFree(hash_map->base.allocator, elm);
     // decrease size
     hash_map->base.size--;
@@ -196,7 +196,7 @@
     struct cx_hash_map_element_s *prev = NULL;
     while (elm && elm->key.hash <= hash) {
         if (elm->key.hash == hash && elm->key.len == key.len) {
-            if (memcmp(elm->key.data.obj, key.data.obj, key.len) == 0) {
+            if (memcmp(elm->key.data, key.data, key.len) == 0) {
                 void *data = NULL;
                 if (destroy) {
                     cx_invoke_destructor(map, elm->data);