diff --git a/src/Amplitude.php b/src/Amplitude.php
index 3aafefa..5d2f58a 100644
--- a/src/Amplitude.php
+++ b/src/Amplitude.php
@@ -257,9 +257,7 @@ public function logEvent($eventType = '', array $eventProperties = [])
             $event->deviceId = $this->deviceId;
         }
         if (!empty($this->userProperties)) {
-            $props = !empty($event->userProperties) ? $event->userProperties : [];
-            $props = array_merge($props, $this->userProperties);
-            $event->userProperties = $props;
+            $event->setUserProperties($this->userProperties);
             $this->resetUserProperties();
         }
 
@@ -355,6 +353,8 @@ public function setDeviceId($deviceId)
     /**
      * Set the user properties, will be sent with the next event sent to Amplitude
      *
+     * Any set with this will take precedence over any set on the Event object
+     *
      * If no events are logged, it will not get sent to Amplitude
      *
      * @param array $userProperties
diff --git a/src/Event.php b/src/Event.php
index 4c53f6c..dbc0f0c 100644
--- a/src/Event.php
+++ b/src/Event.php
@@ -100,6 +100,17 @@ public function __construct(array $data = [])
         }
     }
 
+    /**
+     * Set the user properties on the event
+     *
+     * @param array $userProperties
+     */
+    public function setUserProperties(array $userProperties)
+    {
+        $props = $this->userProperties ?: [];
+        $this->userProperties = array_merge($props, $userProperties);
+        return $this;
+    }
 
     /**
      * Set a value in the event.
diff --git a/test/AmplitudeTest.php b/test/AmplitudeTest.php
index 34acf40..cc7710e 100644
--- a/test/AmplitudeTest.php
+++ b/test/AmplitudeTest.php
@@ -322,4 +322,24 @@ public function testOptOut()
             ->queueEvent('Another Queued Event');
         $this->assertTrue($amplitude->getOptOut());
     }
+
+    public function testSetUserProperties()
+    {
+        $userProps = ['dob' => 'tomorrow', 'gender' => 'f'];
+        $amplitude = new Amplitude();
+        $amplitude->setUserProperties($userProps);
+        $this->assertSame($userProps, $amplitude->getUserProperties());
+        $userProps2 = ['dob' => 'yesterday', 'name' => 'Baby'];
+        $expected = [
+            'dob' => 'yesterday',
+            'gender' => 'f',
+            'name' => 'Baby',
+        ];
+        $amplitude->setUserProperties($userProps2);
+        $this->assertSame(
+            $expected,
+            $amplitude->getUserProperties(),
+            'Second call to setUserProperties should set properties, without removing existing'
+        );
+    }
 }
diff --git a/test/EventTest.php b/test/EventTest.php
index 1967100..1315658 100644
--- a/test/EventTest.php
+++ b/test/EventTest.php
@@ -201,4 +201,28 @@ public function testUnsetProperty()
         unset($event->userId);
         $this->assertEmpty($event->userId, 'Should unset built-in properties with magic unset');
     }
+
+    public function testSetUserProperties()
+    {
+        $userProps = ['dob' => 'tomorrow', 'gender' => 'f'];
+        $event = new Event();
+        $event->setUserProperties($userProps);
+        $this->assertSame(
+            ['user_properties' => $userProps],
+            $event->toArray(),
+            'Should set user properties in user_properties'
+        );
+        $userProps2 = ['dob' => 'yesterday', 'name' => 'Baby'];
+        $expected = [
+            'dob' => 'yesterday',
+            'gender' => 'f',
+            'name' => 'Baby',
+        ];
+        $event->setUserProperties($userProps2);
+        $this->assertSame(
+            ['user_properties' => $expected],
+            $event->toArray(),
+            'Second call to setUserProperties should update properties, not remove existing'
+        );
+    }
 }