diff --git a/src/UDPC_HashMap.c b/src/UDPC_HashMap.c
index ef09703..90d14fc 100644
--- a/src/UDPC_HashMap.c
+++ b/src/UDPC_HashMap.c
@@ -90,6 +90,8 @@ void* UDPC_HashMap_insert(UDPC_HashMap *hm, uint32_t key, void *data)
         }
     }
 
+    UDPC_HashMap_remove(hm, key);
+
     uint32_t hash = UDPC_HASH32(key) % hm->capacity;
 
     char *temp = malloc(sizeof(uint32_t) + hm->unitSize);
diff --git a/src/UDPC_HashMap.h b/src/UDPC_HashMap.h
index 3aadd9c..c91caeb 100644
--- a/src/UDPC_HashMap.h
+++ b/src/UDPC_HashMap.h
@@ -46,6 +46,8 @@ void UDPC_HashMap_destroy(UDPC_HashMap *hashMap);
  * Note if size already equals capacity, the hash map's capacity is doubled
  * with UDPC_HashMap_realloc(). realloc requires rehashing of all items which
  * may be costly.
+ * If an item with the same key already exists in the hash map, it will be
+ * replaced.
  * \return Internally managed pointer to inserted data, NULL on fail
  */
 void* UDPC_HashMap_insert(UDPC_HashMap *hm, uint32_t key, void *data);