diff --git a/src/websockets/handshake.py b/src/websockets/handshake.py
index 646b6dba4..cc6d1973e 100644
--- a/src/websockets/handshake.py
+++ b/src/websockets/handshake.py
@@ -31,9 +31,9 @@
 import random
 from typing import List
 
-from .exceptions import InvalidHeader, InvalidHeaderValue, InvalidUpgrade
+from .exceptions import InvalidHeaderValue, InvalidUpgrade
 from .headers import ConnectionOption, UpgradeProtocol, parse_connection, parse_upgrade
-from .http import Headers, MultipleValuesError
+from .http import Headers
 
 
 __all__ = ["build_request", "check_request", "build_response", "check_response"]
@@ -92,30 +92,16 @@ def check_request(headers: Headers) -> str:
     if not (len(upgrade) == 1 and upgrade[0].lower() == "websocket"):
         raise InvalidUpgrade("Upgrade", ", ".join(upgrade))
 
-    try:
-        s_w_key = headers["Sec-WebSocket-Key"]
-    except KeyError:
-        raise InvalidHeader("Sec-WebSocket-Key")
-    except MultipleValuesError:
-        raise InvalidHeader(
-            "Sec-WebSocket-Key", "more than one Sec-WebSocket-Key header found"
-        )
+    s_w_key = headers.get_safe("Sec-WebSocket-Key")
 
     try:
         raw_key = base64.b64decode(s_w_key.encode(), validate=True)
-    except binascii.Error:
-        raise InvalidHeaderValue("Sec-WebSocket-Key", s_w_key)
+    except binascii.Error as exc:
+        raise InvalidHeaderValue("Sec-WebSocket-Key", s_w_key) from exc
     if len(raw_key) != 16:
         raise InvalidHeaderValue("Sec-WebSocket-Key", s_w_key)
 
-    try:
-        s_w_version = headers["Sec-WebSocket-Version"]
-    except KeyError:
-        raise InvalidHeader("Sec-WebSocket-Version")
-    except MultipleValuesError:
-        raise InvalidHeader(
-            "Sec-WebSocket-Version", "more than one Sec-WebSocket-Version header found"
-        )
+    s_w_version = headers.get_safe("Sec-WebSocket-Version")
 
     if s_w_version != "13":
         raise InvalidHeaderValue("Sec-WebSocket-Version", s_w_version)
@@ -169,14 +155,7 @@ def check_response(headers: Headers, key: str) -> None:
     if not (len(upgrade) == 1 and upgrade[0].lower() == "websocket"):
         raise InvalidUpgrade("Upgrade", ", ".join(upgrade))
 
-    try:
-        s_w_accept = headers["Sec-WebSocket-Accept"]
-    except KeyError:
-        raise InvalidHeader("Sec-WebSocket-Accept")
-    except MultipleValuesError:
-        raise InvalidHeader(
-            "Sec-WebSocket-Accept", "more than one Sec-WebSocket-Accept header found"
-        )
+    s_w_accept = headers.get_safe("Sec-WebSocket-Accept")
 
     if s_w_accept != accept(key):
         raise InvalidHeaderValue("Sec-WebSocket-Accept", s_w_accept)
diff --git a/src/websockets/http.py b/src/websockets/http.py
index f87bfb76a..6e4400924 100644
--- a/src/websockets/http.py
+++ b/src/websockets/http.py
@@ -292,6 +292,16 @@ def copy(self) -> "Headers":
         copy._list = self._list.copy()
         return copy
 
+    def get_safe(self, header: str) -> str:
+        from .exceptions import InvalidHeader
+
+        try:
+            return self[header]
+        except KeyError as exc:
+            raise InvalidHeader(header) from exc
+        except MultipleValuesError as exc:
+            raise InvalidHeader(header, f"more than one {header} header found") from exc
+
     # Collection methods
 
     def __contains__(self, key: object) -> bool: