diff --git a/lib/core/common.py b/lib/core/common.py
index 1faef14ac..08e6cc46e 100755
--- a/lib/core/common.py
+++ b/lib/core/common.py
@@ -1007,6 +1007,14 @@ def sanitizeStr(value):
 
     return getUnicode(value).replace("\n", " ").replace("\r", "")
 
+def getHeader(headers, key):
+    retVal = None
+    for _ in (headers or {}):
+        if _.upper() == key.upper():
+            retVal = headers[_]
+            break
+    return retVal
+
 def checkFile(filename):
     """
     Checks for file existence and readability
diff --git a/lib/request/connect.py b/lib/request/connect.py
index 470c3dcc9..9951ed5d0 100644
--- a/lib/request/connect.py
+++ b/lib/request/connect.py
@@ -37,6 +37,7 @@ from lib.core.common import evaluateCode
 from lib.core.common import extractRegexResult
 from lib.core.common import findMultipartPostBoundary
 from lib.core.common import getCurrentThreadData
+from lib.core.common import getHeader
 from lib.core.common import getHostHeader
 from lib.core.common import getRequestHeader
 from lib.core.common import getUnicode
@@ -338,16 +339,16 @@ class Connect(object):
             if kb.proxyAuthHeader:
                 headers[HTTP_HEADER.PROXY_AUTHORIZATION] = kb.proxyAuthHeader
 
-            if HTTP_HEADER.ACCEPT not in headers:
+            if not getHeader(headers, HTTP_HEADER.ACCEPT):
                 headers[HTTP_HEADER.ACCEPT] = HTTP_ACCEPT_HEADER_VALUE
 
-            if HTTP_HEADER.HOST not in headers or not target:
+            if not getHeader(headers, HTTP_HEADER.HOST) or not target:
                 headers[HTTP_HEADER.HOST] = getHostHeader(url)
 
-            if HTTP_HEADER.ACCEPT_ENCODING not in headers:
+            if not getHeader(headers, HTTP_HEADER.ACCEPT_ENCODING):
                 headers[HTTP_HEADER.ACCEPT_ENCODING] = HTTP_ACCEPT_ENCODING_HEADER_VALUE if kb.pageCompress else "identity"
 
-            if post is not None and HTTP_HEADER.CONTENT_TYPE not in headers:
+            if post is not None and not getHeader(headers, HTTP_HEADER.CONTENT_TYPE):
                 headers[HTTP_HEADER.CONTENT_TYPE] = POST_HINT_CONTENT_TYPES.get(kb.postHint, DEFAULT_CONTENT_TYPE)
 
             if headers.get(HTTP_HEADER.CONTENT_TYPE) == POST_HINT_CONTENT_TYPES[POST_HINT.MULTIPART]: