diff --git a/README.md b/README.md
index 4bac1398..e9c4cefb 100644
--- a/README.md
+++ b/README.md
@@ -173,7 +173,7 @@ async def index():
 
 By default the `default_key_builder` builtin key builder is used; this creates a
 cache key from the function module and name, and the positional and keyword
-arguments converted to their `repr()` representations, encoded as a MD5 hash.
+arguments converted to their `repr()` representations, encoded as a BLAKE2 hash.
 You can provide your own by passing a key builder in to `@cache()`, or to
 `FastAPICache.init()` to apply globally.
 
diff --git a/changelog.d/264.feature.md b/changelog.d/264.feature.md
new file mode 100644
index 00000000..8c6da519
--- /dev/null
+++ b/changelog.d/264.feature.md
@@ -0,0 +1 @@
+Use BLAKE2 instead of MD5.
\ No newline at end of file
diff --git a/fastapi_cache/key_builder.py b/fastapi_cache/key_builder.py
index feee3a63..9d60a555 100644
--- a/fastapi_cache/key_builder.py
+++ b/fastapi_cache/key_builder.py
@@ -14,7 +14,7 @@ def default_key_builder(
     args: Tuple[Any, ...],
     kwargs: Dict[str, Any],
 ) -> str:
-    cache_key = hashlib.md5(  # noqa: S324
+    cache_key = hashlib.blake2b(
         f"{func.__module__}:{func.__name__}:{args}:{kwargs}".encode()
     ).hexdigest()
     return f"{namespace}:{cache_key}"