diff --git a/doc/admin-guide/plugins/cachekey.en.rst b/doc/admin-guide/plugins/cachekey.en.rst
index 5342d8b52b8..51f4ef174a8 100644
--- a/doc/admin-guide/plugins/cachekey.en.rst
+++ b/doc/admin-guide/plugins/cachekey.en.rst
@@ -70,20 +70,29 @@ Cache key structure and related plugin parameters
 
 ::
 
-  Optional components      | ┌─────────────────┬──────────────────┬──────────────────────┐
+  Optional components      | ┌─────────────────┬────────────── ───┬──────────────────────┐
   (included in this order) | │ --static-prefix | --capture-prefix │ --capture-prefix-uri │
                            | ├─────────────────┴──────────────────┴──────────────────────┤
-  Default values if no     | │ /host/port                                                |
+  Default values if no     | │ /host/port or scheme://host:port (see the table below)    |
   optional components      | └───────────────────────────────────────────────────────────┘
   configured               |
 
+  ┌────────────────────┬─────────────────────────┬──────────────────────┐
+  │ --canonical-prefix |  default value if no    │ input used for       │
+  │                    |  prefix parameters used │ --capture-prefix     │
+  ├────────────────────┴─────────────────────────┴──────────────────────┤
+  │ fasle              | /host/port              | host:port            |
+  ├────────────────────┴─────────────────────────┴──────────────────────┤
+  │ true               | scheme://host:port      | scheme://host:port   |
+  └──────────────────────────────────────────────┴──────────────────────┘
+
+
 * ``--static-prefix=<value>`` (default: empty string) - if specified and not an empty string the ``<value>`` will be added to the cache key.
-* ``--capture-prefix=<capture_definition>`` (default: empty string) - if specified and not empty then strings are captured from ``host:port`` based on the ``<capture_definition>`` and are added to the cache key.
+* ``--capture-prefix=<capture_definition>`` (default: empty string) - if specified and not empty then strings are captured based on the value of ``--canonical-prefix`` parameter (see the table above) and ``<capture_definition>`` and are added to the cache key.
 * ``--capture-prefix-uri=<capture_definition>`` (default: empty string) - if specified and not empty then strings are captured from the entire URI based on the ``<capture_definition>`` and are added to the cache key.
 * If any of the "Prefix" related plugin parameters are used together in the plugin configuration they are added to the cache key in the order shown in the diagram.
-* ``--remove-prefix=<true|false|yes|no|0|1`` (default: false) - if specified the prefix elements (host, port) are not processed nor appended to the cachekey. All prefix related plugin parameters are ignored if this parameter is ``true``, ``yes`` or ``1``.
-
-
+* ``--remove-prefix=true|false|yes|no|0|1`` (default: false) - if specified the prefix elements (host, port) are not processed nor appended to the cachekey. All prefix related plugin parameters are ignored if this parameter is ``true``, ``yes`` or ``1``.
+* ``--canonical-prefix=true|false|yes|no|0|1`` (default: false) - impacts the input of regex operation when ``--capture-prefix`` is used and the default value if no prefix parameters are used (see the table above).
 
 "User-Agent" section
 ^^^^^^^^^^^^^^^^^^^^
diff --git a/plugins/cachekey/cachekey.cc b/plugins/cachekey/cachekey.cc
index 9cf4454210f..95640e19005 100644
--- a/plugins/cachekey/cachekey.cc
+++ b/plugins/cachekey/cachekey.cc
@@ -188,6 +188,51 @@ getUri(TSMBuffer buf, TSMLoc url)
   return uri;
 }
 
+static String
+getCanonicalUrl(TSMBuffer buf, TSMLoc url, bool canonicalPrefix, bool provideDefaultKey)
+{
+  String canonicalUrl;
+
+  String scheme;
+  int schemeLen;
+  const char *schemePtr = TSUrlSchemeGet(buf, url, &schemeLen);
+  if (nullptr != schemePtr && 0 != schemeLen) {
+    scheme.assign(schemePtr, schemeLen);
+  } else {
+    CacheKeyError("failed to get scheme");
+    return canonicalUrl;
+  }
+
+  String host;
+  int hostLen;
+  const char *hostPtr = TSUrlHostGet(buf, url, &hostLen);
+  if (nullptr != hostPtr && 0 != hostLen) {
+    host.assign(hostPtr, hostLen);
+  } else {
+    CacheKeyError("failed to get host");
+    return canonicalUrl;
+  }
+
+  String port;
+  int portInt = TSUrlPortGet(buf, url);
+  ::append(port, portInt);
+
+  if (canonicalPrefix) {
+    /* return the same for both regex input or default key, results in 'scheme://host:port' */
+    canonicalUrl.assign(scheme).append("://").append(host).append(":").append(port);
+  } else {
+    if (provideDefaultKey) {
+      /* return the key default - results in '/host/port' */
+      canonicalUrl.assign("/").append(host).append("/").append(port);
+    } else {
+      /* return regex input string - results in 'host:port' (use-case kept for compatibility reasons) */
+      canonicalUrl.assign(host).append(":").append(port);
+    }
+  }
+
+  return canonicalUrl;
+}
+
 /**
  * @brief Constructor setting up the cache key prefix, initializing request info.
  * @param txn transaction handle.
@@ -289,6 +334,16 @@ CacheKey::append(const String &s)
   ::appendEncoded(_key, s.data(), s.size());
 }
 
+void
+CacheKey::append(const String &s, bool useSeparator)
+{
+  if (useSeparator) {
+    append(s);
+  } else {
+    _key.append(s);
+  }
+}
+
 /**
  * @brief Append null-terminated C-style string to the key.
  * @param s null-terminated C-style string.
@@ -319,42 +374,31 @@ CacheKey::append(const char *s, unsigned n)
  * @param prefix if not empty string will append the static prefix to the cache key.
  * @param prefixCapture if not empty will append regex capture/replacement from the host:port.
  * @param prefixCaptureUri if not empty will append regex capture/replacement from the whole URI.
+ * @param canonicalPrefix false - use 'host:port' as starting point of all transformations, true - use 'scheme://host:port'
  * @note if both prefix and pattern are not empty prefix will be added first, followed by the results from pattern.
  */
 void
-CacheKey::appendPrefix(const String &prefix, Pattern &prefixCapture, Pattern &prefixCaptureUri)
+CacheKey::appendPrefix(const String &prefix, Pattern &prefixCapture, Pattern &prefixCaptureUri, bool canonicalPrefix)
 {
-  // "true" would mean that the plugin config meant to override the default prefix (host:port).
+  // "true" would mean that the plugin config meant to override the default prefix, "false" means use default.
   bool customPrefix = false;
-  String host;
-  int port = 0;
+
+  /* For all the following operations if a canonical prefix is required then appned to the key with no separator
+   * to leave the door open for potential valid host name formed in the final resulting cache key. */
 
   if (!prefix.empty()) {
     customPrefix = true;
-    append(prefix);
+    append(prefix, /* useSeparator */ !canonicalPrefix);
     CacheKeyDebug("added static prefix, key: '%s'", _key.c_str());
   }
 
-  int hostLen;
-  const char *hostPtr = TSUrlHostGet(_buf, _url, &hostLen);
-  if (nullptr != hostPtr && 0 != hostLen) {
-    host.assign(hostPtr, hostLen);
-  } else {
-    CacheKeyError("failed to get host");
-  }
-  port = TSUrlPortGet(_buf, _url);
-
   if (!prefixCapture.empty()) {
     customPrefix = true;
 
-    String hostAndPort;
-    hostAndPort.append(host).append(":");
-    ::append(hostAndPort, port);
-
     StringVector captures;
-    if (prefixCapture.process(hostAndPort, captures)) {
+    if (prefixCapture.process(getCanonicalUrl(_buf, _url, canonicalPrefix, /* provideDefaultKey */ false), captures)) {
       for (auto &capture : captures) {
-        append(capture);
+        append(capture, /* useSeparator */ !canonicalPrefix);
       }
       CacheKeyDebug("added host:port capture prefix, key: '%s'", _key.c_str());
     }
@@ -368,7 +412,7 @@ CacheKey::appendPrefix(const String &prefix, Pattern &prefixCapture, Pattern &pr
       StringVector captures;
       if (prefixCaptureUri.process(uri, captures)) {
         for (auto &capture : captures) {
-          append(capture);
+          append(capture, /* useSeparator */ !canonicalPrefix);
         }
         CacheKeyDebug("added URI capture prefix, key: '%s'", _key.c_str());
       }
@@ -376,8 +420,8 @@ CacheKey::appendPrefix(const String &prefix, Pattern &prefixCapture, Pattern &pr
   }
 
   if (!customPrefix) {
-    append(host);
-    append(port);
+    /* nothing was customized => default prefix */
+    append(getCanonicalUrl(_buf, _url, canonicalPrefix, /* provideDefaultKey */ true), /* useSeparator */ false);
     CacheKeyDebug("added default prefix, key: '%s'", _key.c_str());
   }
 }
diff --git a/plugins/cachekey/cachekey.h b/plugins/cachekey/cachekey.h
index 7ea058cb6cf..0922ed104ab 100644
--- a/plugins/cachekey/cachekey.h
+++ b/plugins/cachekey/cachekey.h
@@ -55,9 +55,10 @@ class CacheKey
 
   void append(unsigned number);
   void append(const String &);
+  void append(const String &s, bool useSeparator);
   void append(const char *s);
   void append(const char *n, unsigned s);
-  void appendPrefix(const String &prefix, Pattern &prefixCapture, Pattern &prefixCaptureUri);
+  void appendPrefix(const String &prefix, Pattern &prefixCapture, Pattern &prefixCaptureUri, bool canonicalPrefix);
   void appendPath(Pattern &pathCapture, Pattern &pathCaptureUri);
   void appendHeaders(const ConfigHeaders &config);
   void appendQuery(const ConfigQuery &config);
diff --git a/plugins/cachekey/configs.cc b/plugins/cachekey/configs.cc
index 2320db14336..a56565c7d93 100644
--- a/plugins/cachekey/configs.cc
+++ b/plugins/cachekey/configs.cc
@@ -397,6 +397,8 @@ Configs::init(int argc, const char *argv[], bool perRemapConfig)
     {const_cast<char *>("separator"), optional_argument, nullptr, 's'},
     {const_cast<char *>("uri-type"), optional_argument, nullptr, 't'},
     {const_cast<char *>("capture-header"), optional_argument, nullptr, 'u'},
+    {const_cast<char *>("canonical-prefix"), optional_argument, nullptr, 'v'},
+    /* reserve 'z' for 'config' files */
     {nullptr, 0, nullptr, 0},
   };
 
@@ -504,6 +506,9 @@ Configs::init(int argc, const char *argv[], bool perRemapConfig)
     case 'u': /* capture-header */
       _headers.addCapture(optarg);
       break;
+    case 'v': /* canonical-prefix */
+      _canonicalPrefix = isTrue(optarg);
+      break;
     }
   }
 
@@ -535,6 +540,12 @@ Configs::pathToBeRemoved()
   return _pathToBeRemoved;
 }
 
+bool
+Configs::canonicalPrefix()
+{
+  return _canonicalPrefix;
+}
+
 void
 Configs::setSeparator(const char *arg)
 {
diff --git a/plugins/cachekey/configs.h b/plugins/cachekey/configs.h
index 947b21931ea..5ff41f03ccc 100644
--- a/plugins/cachekey/configs.h
+++ b/plugins/cachekey/configs.h
@@ -162,6 +162,11 @@ class Configs
    */
   bool pathToBeRemoved();
 
+  /**
+   * @brief keep URI scheme and authority elements.
+   */
+  bool canonicalPrefix();
+
   /**
    * @brief set the cache key elements separator string.
    */
@@ -205,6 +210,7 @@ class Configs
 
   bool _prefixToBeRemoved  = false; /**< @brief instructs the prefix (i.e. host:port) not to added to the cache key */
   bool _pathToBeRemoved    = false; /**< @brief instructs the path not to added to the cache key */
+  bool _canonicalPrefix    = false; /**< @brief keep the URI scheme and authority element used as input to transforming into key */
   String _separator        = "/";   /**< @brief a separator used to separate the cache key elements extracted from the URI */
   CacheKeyUriType _uriType = REMAP; /**< @brief shows which URI the cache key will be based on */
 };
diff --git a/plugins/cachekey/plugin.cc b/plugins/cachekey/plugin.cc
index 43bad79e3c0..afb9503b0ce 100644
--- a/plugins/cachekey/plugin.cc
+++ b/plugins/cachekey/plugin.cc
@@ -43,7 +43,7 @@ setCacheKey(TSHttpTxn txn, Configs *config, TSRemapRequestInfo *rri = nullptr)
 
   /* Append custom prefix or the host:port */
   if (!config->prefixToBeRemoved()) {
-    cachekey.appendPrefix(config->_prefix, config->_prefixCapture, config->_prefixCaptureUri);
+    cachekey.appendPrefix(config->_prefix, config->_prefixCapture, config->_prefixCaptureUri, config->canonicalPrefix());
   }
   /* Classify User-Agent and append the class name to the cache key if matched. */
   cachekey.appendUaClass(config->_classifier);