diff --git a/Lib/http/client.py b/Lib/http/client.py
--- a/Lib/http/client.py
+++ b/Lib/http/client.py
@@ -679,6 +679,40 @@
             total_bytes += n
         return total_bytes
 
+    def peek(self, n=None):
+        # Having this enables IOBase.readline() to read more than one
+        # byte at a time
+        if self.fp is None or self._method == "HEAD":
+            return b""
+        if self.chunked:
+            return self._peek_chunked(n)
+        return self.fp.peek(n)
+
+    def _peek_chunked(self, n):
+        # Peek at most one chunk into the buffer
+        if self.chunk_left is not None:
+            # Peek into the current chunk
+            if n < 0:
+                n = self.chunk_left
+            else:
+                n = min(n, self.chunk_left)
+            return self.fp.peek(n)
+        # Peek into the next chunk
+        peeked = self.fp.peek(n)
+        i = peeked.find(b"\n")
+        if i > 0:
+            head = peeked[:i]
+            j = head.find(b";")
+            if j >= 0:
+                head = head[:j] # strip chunk-extensions
+            try:
+                chunklen = int(head, 16)
+            except ValueError:
+                return b""
+            i += 1 # advance to chunk start
+            return peeked[i:chunklen+i]
+        return b""
+
     def fileno(self):
         return self.fp.fileno()