diff --git a/src/Monolog/Handler/ChromePHPHandler.php b/src/Monolog/Handler/ChromePHPHandler.php
index 75fa8025..ff7a7809 100644
--- a/src/Monolog/Handler/ChromePHPHandler.php
+++ b/src/Monolog/Handler/ChromePHPHandler.php
@@ -100,15 +100,19 @@ class ChromePHPHandler extends AbstractProcessingHandler
      */
     protected function send()
     {
-        if (self::$overflowed) {
+        if (self::$overflowed || !self::$sendHeaders) {
             return;
         }
 
         if (!self::$initialized) {
-            self::$sendHeaders = $this->headersAccepted();
-            self::$json['request_uri'] = isset($_SERVER['REQUEST_URI']) ? $_SERVER['REQUEST_URI'] : '';
-
             self::$initialized = true;
+
+            self::$sendHeaders = $this->headersAccepted();
+            if (!self::$sendHeaders) {
+                return;
+            }
+
+            self::$json['request_uri'] = isset($_SERVER['REQUEST_URI']) ? $_SERVER['REQUEST_URI'] : '';
         }
 
         $json = @json_encode(self::$json);
diff --git a/src/Monolog/Handler/FirePHPHandler.php b/src/Monolog/Handler/FirePHPHandler.php
index 376143f0..fee47950 100644
--- a/src/Monolog/Handler/FirePHPHandler.php
+++ b/src/Monolog/Handler/FirePHPHandler.php
@@ -131,15 +131,22 @@ class FirePHPHandler extends AbstractProcessingHandler
      */
     protected function write(array $record)
     {
+        if (!self::$sendHeaders) {
+            return;
+        }
+
         // WildFire-specific headers must be sent prior to any messages
         if (!self::$initialized) {
+            self::$initialized = true;
+
             self::$sendHeaders = $this->headersAccepted();
+            if (!self::$sendHeaders) {
+                return;
+            }
 
             foreach ($this->getInitHeaders() as $header => $content) {
                 $this->sendHeader($header, $content);
             }
-
-            self::$initialized = true;
         }
 
         $header = $this->createRecordHeader($record);
diff --git a/tests/Monolog/Handler/ChromePHPHandlerTest.php b/tests/Monolog/Handler/ChromePHPHandlerTest.php
index 9fa4d506..2f55faf8 100644
--- a/tests/Monolog/Handler/ChromePHPHandlerTest.php
+++ b/tests/Monolog/Handler/ChromePHPHandlerTest.php
@@ -22,6 +22,7 @@ class ChromePHPHandlerTest extends TestCase
     protected function setUp()
     {
         TestChromePHPHandler::reset();
+        $_SERVER['HTTP_USER_AGENT'] = 'Monolog Test; Chrome/1.0';
     }
 
     public function testHeaders()
@@ -124,6 +125,7 @@ class TestChromePHPHandler extends ChromePHPHandler
     {
         self::$initialized = false;
         self::$overflowed = false;
+        self::$sendHeaders = true;
         self::$json['rows'] = array();
     }
 
diff --git a/tests/Monolog/Handler/FirePHPHandlerTest.php b/tests/Monolog/Handler/FirePHPHandlerTest.php
index 2b7b76d9..0eb10a63 100644
--- a/tests/Monolog/Handler/FirePHPHandlerTest.php
+++ b/tests/Monolog/Handler/FirePHPHandlerTest.php
@@ -22,6 +22,7 @@ class FirePHPHandlerTest extends TestCase
     public function setUp()
     {
         TestFirePHPHandler::reset();
+        $_SERVER['HTTP_USER_AGENT'] = 'Monolog Test; FirePHP/1.0';
     }
 
     public function testHeaders()
@@ -79,6 +80,7 @@ class TestFirePHPHandler extends FirePHPHandler
     public static function reset()
     {
         self::$initialized = false;
+        self::$sendHeaders = true;
         self::$messageIndex = 1;
     }