diff --git a/src/config.json b/src/config.json
index b59e251b..4c17dfe5 100644
--- a/src/config.json
+++ b/src/config.json
@@ -1,37 +1,38 @@
 {
-    "algo": "cryptonight",  // cryptonight (default) or cryptonight-lite
-    "av": 0,                // algorithm variation, 0 auto select
-    "background": false,    // true to run the miner in the background
-    "colors": true,         // false to disable colored output    
-    "cpu-affinity": null,   // set process affinity to CPU core(s), mask "0x3" for cores 0 and 1
-    "cpu-priority": null,   // set process priority (0 idle, 2 normal to 5 highest)
-    "donate-level": 5,      // donate level, mininum 1%
-    "log-file": null,       // log all output to a file, example: "c:/some/path/xmrig.log"
-    "max-cpu-usage": 75,    // maximum CPU usage for automatic mode, usually limiting factor is CPU cache not this option.  
-    "print-time": 60,       // print hashrate report every N seconds
-    "retries": 5,           // number of times to retry before switch to backup server
-    "retry-pause": 5,       // time to pause between retries
-    "safe": false,          // true to safe adjust threads and av settings for current CPU
-    "syslog": false,        // use system log for output messages
-    "threads": null,        // number of miner threads
+    "algo": "cryptonight",                      // cryptonight (default) or cryptonight-lite
+    "av": 0,                                    // algorithm variation, 0 auto select
+    "doublehash-thread-mask" : null,            // for av=2/4 only, limits doublehash to given threads (mask), (default: all threads)
+    "background": false,                        // true to run the miner in the background
+    "colors": true,                             // false to disable colored output
+    "cpu-affinity": null,                       // set process affinity to CPU core(s), mask "0x3" for cores 0 and 1
+    "cpu-priority": null,                       // set process priority (0 idle, 2 normal to 5 highest)
+    "donate-level": 5,                          // donate level, mininum 1%
+    "log-file": null,                           // log all output to a file, example: "c:/some/path/xmrig.log"
+    "max-cpu-usage": 75,                        // maximum CPU usage for automatic mode, usually limiting factor is CPU cache not this option.
+    "print-time": 60,                           // print hashrate report every N seconds
+    "retries": 5,                               // number of times to retry before switch to backup server
+    "retry-pause": 5,                           // time to pause between retries
+    "safe": false,                              // true to safe adjust threads and av settings for current CPU
+    "syslog": false,                            // use system log for output messages
+    "threads": null,                            // number of miner threads
     "pools": [
         {
-            "url": "",                         // URL of mining server
-            "user": "",                        // username for mining server
-            "pass": "x",                       // password for mining server
-            "keepalive": true,                 // send keepalived for prevent timeout (need pool support)
-            "nicehash": false                  // enable nicehash/xmrig-proxy support
+            "url": "",                          // URL of mining server
+            "user": "",                         // username for mining server
+            "pass": "x",                        // password for mining server
+            "keepalive": true,                  // send keepalived for prevent timeout (need pool support)
+            "nicehash": false                   // enable nicehash/xmrig-proxy support
         }
     ],
     "api": {
-        "port": 0,                             // port for the miner API https://github.com/xmrig/xmrig/wiki/API
-        "access-token": null,                  // access token for API
-        "worker-id": null                      // custom worker-id for API
+        "port": 0,                              // port for the miner API https://github.com/xmrig/xmrig/wiki/API
+        "access-token": null,                   // access token for API
+        "worker-id": null                       // custom worker-id for API
     },
     "cc-client": {
-        "url": "localhost:3344",               // url of the CC Server (ip:port)
-        "access-token": "mySecret",            // access token for CC Server (has to be the same in config_cc.json)
-        "worker-id": null,                     // custom worker-id for CC Server (otherwise hostname is used)
-        "update-interval-s": 10                // status update interval in seconds (default: 10 min: 1)
+        "url": "localhost:3344",                // url of the CC Server (ip:port)
+        "access-token": "mySecret",             // access token for CC Server (has to be the same in config_cc.json)
+        "worker-id": null,                      // custom worker-id for CC Server (otherwise hostname is used)
+        "update-interval-s": 10                 // status update interval in seconds (default: 10 min: 1)
     }
 }
diff --git a/src/default_config.json b/src/default_config.json
index 255d2bad..4c17dfe5 100644
--- a/src/default_config.json
+++ b/src/default_config.json
@@ -1,37 +1,38 @@
 {
-    "algo": "cryptonight",  // cryptonight (default) or cryptonight-lite
-    "av": 0,                // algorithm variation, 0 auto select
-    "background": false,    // true to run the miner in the background
-    "colors": true,         // false to disable colored output
-    "cpu-affinity": null,   // set process affinity to CPU core(s), mask "0x3" for cores 0 and 1
-    "cpu-priority": null,   // set process priority (0 idle, 2 normal to 5 highest)
-    "donate-level": 5,      // donate level, mininum 1%
-    "log-file": null,       // log all output to a file, example: "c:/some/path/xmrig.log"
-    "max-cpu-usage": 75,    // maximum CPU usage for automatic mode, usually limiting factor is CPU cache not this option.
-    "print-time": 60,       // print hashrate report every N seconds
-    "retries": 5,           // number of times to retry before switch to backup server
-    "retry-pause": 5,       // time to pause between retries
-    "safe": false,          // true to safe adjust threads and av settings for current CPU
-    "syslog": false,        // use system log for output messages
-    "threads": null,        // number of miner threads
+    "algo": "cryptonight",                      // cryptonight (default) or cryptonight-lite
+    "av": 0,                                    // algorithm variation, 0 auto select
+    "doublehash-thread-mask" : null,            // for av=2/4 only, limits doublehash to given threads (mask), (default: all threads)
+    "background": false,                        // true to run the miner in the background
+    "colors": true,                             // false to disable colored output
+    "cpu-affinity": null,                       // set process affinity to CPU core(s), mask "0x3" for cores 0 and 1
+    "cpu-priority": null,                       // set process priority (0 idle, 2 normal to 5 highest)
+    "donate-level": 5,                          // donate level, mininum 1%
+    "log-file": null,                           // log all output to a file, example: "c:/some/path/xmrig.log"
+    "max-cpu-usage": 75,                        // maximum CPU usage for automatic mode, usually limiting factor is CPU cache not this option.
+    "print-time": 60,                           // print hashrate report every N seconds
+    "retries": 5,                               // number of times to retry before switch to backup server
+    "retry-pause": 5,                           // time to pause between retries
+    "safe": false,                              // true to safe adjust threads and av settings for current CPU
+    "syslog": false,                            // use system log for output messages
+    "threads": null,                            // number of miner threads
     "pools": [
         {
-            "url": "",                         // URL of mining server
-            "user": "",                        // username for mining server
-            "pass": "x",                       // password for mining server
-            "keepalive": true,                 // send keepalived for prevent timeout (need pool support)
-            "nicehash": false                  // enable nicehash/xmrig-proxy support
+            "url": "",                          // URL of mining server
+            "user": "",                         // username for mining server
+            "pass": "x",                        // password for mining server
+            "keepalive": true,                  // send keepalived for prevent timeout (need pool support)
+            "nicehash": false                   // enable nicehash/xmrig-proxy support
         }
     ],
     "api": {
-        "port": 0,                             // port for the miner API https://github.com/xmrig/xmrig/wiki/API
-        "access-token": null,                  // access token for API
-        "worker-id": null                      // custom worker-id for API
+        "port": 0,                              // port for the miner API https://github.com/xmrig/xmrig/wiki/API
+        "access-token": null,                   // access token for API
+        "worker-id": null                       // custom worker-id for API
     },
     "cc-client": {
-        "url": "localhost:3344",               // url of the CC Server (ip:port)
-        "access-token": "mySecret",            // access token for CC Server (has to be the same in config_cc.json)
-        "worker-id": null,                     // custom worker-id for CC Server (otherwise hostname is used)
-        "update-interval-s": 10                // status update interval in seconds (default: 10 min: 1)
+        "url": "localhost:3344",                // url of the CC Server (ip:port)
+        "access-token": "mySecret",             // access token for CC Server (has to be the same in config_cc.json)
+        "worker-id": null,                      // custom worker-id for CC Server (otherwise hostname is used)
+        "update-interval-s": 10                 // status update interval in seconds (default: 10 min: 1)
     }
-}
\ No newline at end of file
+}