diff --git a/included_dependencies/urllib3/_version.py b/included_dependencies/urllib3/_version.py
index 2dba29e3..97f83dc2 100644
--- a/included_dependencies/urllib3/_version.py
+++ b/included_dependencies/urllib3/_version.py
@@ -1,2 +1,2 @@
 # This file is protected via CODEOWNERS
-__version__ = "1.26.2"
+__version__ = "1.26.3"
diff --git a/included_dependencies/urllib3/connection.py b/included_dependencies/urllib3/connection.py
index 660d679c..9066e6ad 100644
--- a/included_dependencies/urllib3/connection.py
+++ b/included_dependencies/urllib3/connection.py
@@ -67,7 +67,7 @@ port_by_scheme = {"http": 80, "https": 443}
 
 # When it comes time to update this value as a part of regular maintenance
 # (ie test_recent_date is failing) update it to ~6 months before the current date.
-RECENT_DATE = datetime.date(2019, 1, 1)
+RECENT_DATE = datetime.date(2020, 7, 1)
 
 _CONTAINS_CONTROL_CHAR_RE = re.compile(r"[^-!#$%&'*+.^_`|~0-9a-zA-Z]")
 
@@ -215,7 +215,7 @@ class HTTPConnection(_HTTPConnection, object):
 
     def putheader(self, header, *values):
         """"""
-        if SKIP_HEADER not in values:
+        if not any(isinstance(v, str) and v == SKIP_HEADER for v in values):
             _HTTPConnection.putheader(self, header, *values)
         elif six.ensure_str(header.lower()) not in SKIPPABLE_HEADERS:
             raise ValueError(
diff --git a/included_dependencies/urllib3/exceptions.py b/included_dependencies/urllib3/exceptions.py
index d69958d5..cba6f3f5 100644
--- a/included_dependencies/urllib3/exceptions.py
+++ b/included_dependencies/urllib3/exceptions.py
@@ -289,7 +289,17 @@ class ProxySchemeUnknown(AssertionError, URLSchemeUnknown):
     # TODO(t-8ch): Stop inheriting from AssertionError in v2.0.
 
     def __init__(self, scheme):
-        message = "Not supported proxy scheme %s" % scheme
+        # 'localhost' is here because our URL parser parses
+        # localhost:8080 -> scheme=localhost, remove if we fix this.
+        if scheme == "localhost":
+            scheme = None
+        if scheme is None:
+            message = "Proxy URL had no scheme, should start with http:// or https://"
+        else:
+            message = (
+                "Proxy URL had unsupported scheme %s, should use http:// or https://"
+                % scheme
+            )
         super(ProxySchemeUnknown, self).__init__(message)