diff --git a/arrays_strings/hash_map/hash_map_challenge.ipynb b/arrays_strings/hash_map/hash_map_challenge.ipynb
index dd1cd55..a89bc5e 100644
--- a/arrays_strings/hash_map/hash_map_challenge.ipynb
+++ b/arrays_strings/hash_map/hash_map_challenge.ipynb
@@ -97,7 +97,7 @@
     "        # TODO: Implement me\n",
     "        pass\n",
     "\n",
-    "    def hash_function(self, key):\n",
+    "    def _hash_function(self, key):\n",
     "        # TODO: Implement me\n",
     "        pass\n",
     "\n",
diff --git a/arrays_strings/hash_map/hash_map_solution.ipynb b/arrays_strings/hash_map/hash_map_solution.ipynb
index 6282a14..40c4298 100644
--- a/arrays_strings/hash_map/hash_map_solution.ipynb
+++ b/arrays_strings/hash_map/hash_map_solution.ipynb
@@ -132,11 +132,11 @@
     "        self.size = size\n",
     "        self.table = [[] for _ in range(self.size)]\n",
     "\n",
-    "    def hash_function(self, key):\n",
+    "    def _hash_function(self, key):\n",
     "        return key % self.size\n",
     "\n",
     "    def set(self, key, value):\n",
-    "        hash_index = self.hash_function(key)\n",
+    "        hash_index = self._hash_function(key)\n",
     "        for item in self.table[hash_index]:\n",
     "            if item.key == key:\n",
     "                item.value = value\n",
@@ -144,14 +144,14 @@
     "        self.table[hash_index].append(Item(key, value))\n",
     "\n",
     "    def get(self, key):\n",
-    "        hash_index = self.hash_function(key)\n",
+    "        hash_index = self._hash_function(key)\n",
     "        for item in self.table[hash_index]:\n",
     "            if item.key == key:\n",
     "                return item.value\n",
     "        raise KeyError('Key not found')\n",
     "\n",
     "    def remove(self, key):\n",
-    "        hash_index = self.hash_function(key)\n",
+    "        hash_index = self._hash_function(key)\n",
     "        for index, item in enumerate(self.table[hash_index]):\n",
     "            if item.key == key:\n",
     "                del self.table[hash_index][index]\n",