diff --git a/src/Prometheus/Storage/Redis.php b/src/Prometheus/Storage/Redis.php
index 091577c..34c3752 100644
--- a/src/Prometheus/Storage/Redis.php
+++ b/src/Prometheus/Storage/Redis.php
@@ -122,9 +122,9 @@ public function updateHistogram(array $data)
         unset($metaData['value']);
         unset($metaData['labelValues']);
         $this->redis->eval(<<<LUA
-local increment = redis.call('hIncrByFloat', KEYS[1], KEYS[2], ARGV[1])
-redis.call('hIncrBy', KEYS[1], KEYS[3], 1)
-if increment == ARGV[1] then
+redis.call('hIncrByFloat', KEYS[1], KEYS[2], ARGV[1])
+local increment = redis.call('hIncrBy', KEYS[1], KEYS[3], 1)
+if increment == 1 then
     redis.call('hSet', KEYS[1], '__meta', ARGV[2])
     redis.call('sAdd', KEYS[4], KEYS[1])
 end
diff --git a/tests/Test/Prometheus/AbstractHistogramTest.php b/tests/Test/Prometheus/AbstractHistogramTest.php
index 358fcad..798a454 100644
--- a/tests/Test/Prometheus/AbstractHistogramTest.php
+++ b/tests/Test/Prometheus/AbstractHistogramTest.php
@@ -177,7 +177,7 @@ public function itShouldObserveValuesOfTypeDouble()
             array(),
             array(0.1, 0.2, 0.3)
         );
-        $histogram->observe(0.11);
+        $histogram->observe(1343.11);
         $histogram->observe(0.3);
         $this->assertThat(
             $this->adapter->collect(),
@@ -200,13 +200,13 @@ public function itShouldObserveValuesOfTypeDouble()
                                     'name' => 'test_some_metric_bucket',
                                     'labelNames' => array('le'),
                                     'labelValues' => array(0.2),
-                                    'value' => 1,
+                                    'value' => 0,
                                 ),
                                 array(
                                     'name' => 'test_some_metric_bucket',
                                     'labelNames' => array('le'),
                                     'labelValues' => array(0.3),
-                                    'value' => 2,
+                                    'value' => 1,
                                 ),
                                 array(
                                     'name' => 'test_some_metric_bucket',
@@ -224,7 +224,7 @@ public function itShouldObserveValuesOfTypeDouble()
                                     'name' => 'test_some_metric_sum',
                                     'labelNames' => array(),
                                     'labelValues' => array(),
-                                    'value' => 0.41,
+                                    'value' => 1343.41000000000000003,
                                 )
                             )
                         )