diff --git a/Include/Fledasty/Core/HashTable.h b/Include/Fledasty/Core/HashTable.h
index e1d0b30..ab26d1e 100644
--- a/Include/Fledasty/Core/HashTable.h
+++ b/Include/Fledasty/Core/HashTable.h
@@ -40,10 +40,10 @@ typedef struct {
     size_t key_byte_size, value_byte_size;
     FledastyDynamicArray *Table;
 
-    size_t (*hash_function)(void *key);
+    size_t (*hash_function)(const void *key);
 } FledastyHashTable;
 
-FledastyError fledasty_hash_table_initialize(FledastyHashTable *new_hash_table, size_t key_byte_size, size_t value_byte_size, size_t (*hash_function)(void *key));
+FledastyError fledasty_hash_table_initialize(FledastyHashTable *new_hash_table, const size_t key_byte_size, const size_t value_byte_size, size_t (*hash_function)(const void *key));
 FledastyError fledasty_hash_table_destroy(FledastyHashTable *current_hash_table);
 
 FledastyError fledasty_hash_table_insert(FledastyHashTable *current_hash_table, void *key, void *value);
diff --git a/Src/Core/HashTable.c b/Src/Core/HashTable.c
index 8e92a31..aacf83a 100644
--- a/Src/Core/HashTable.c
+++ b/Src/Core/HashTable.c
@@ -28,7 +28,7 @@
 
 static const int FLEDASTY_HASH_TABLE_SIZE_THRESHOLD = 75;
 
-FledastyError fledasty_hash_table_initialize(FledastyHashTable *new_hash_table, size_t key_byte_size, size_t value_byte_size, size_t (*hash_function)(void *key)) {
+FledastyError fledasty_hash_table_initialize(FledastyHashTable *new_hash_table, const size_t key_byte_size, const size_t value_byte_size, size_t (*hash_function)(const void *key)) {
     if (new_hash_table == NULL || hash_function == NULL) {
         return FLEDASTY_ERROR_INVALID_POINTER;
     }
diff --git a/Tests/Main.c b/Tests/Main.c
index fba8285..4ce0f77 100644
--- a/Tests/Main.c
+++ b/Tests/Main.c
@@ -29,7 +29,7 @@
 #include <Fledasty/Core/HashTable.h>
 #include <Fledasty/Strings/UTF8String.h>
 
-static inline size_t integer_hash_function(void *key) { return *(size_t*)key; }
+static inline size_t integer_hash_function(const void *key) { return *(size_t*)key; }
 
 int main() {
     FledastyQueue test_queue;