diff --git a/Changes.md b/Changes.md
index a2636a811ed..68290067049 100644
--- a/Changes.md
+++ b/Changes.md
@@ -22,6 +22,7 @@ API
 - TextWidget, MultilineTextWidget :
   - Added `setPlaceholderText()` and `getPlaceholderText()` methods.
   - Added `placeholderText` constructor argument.
+- BackgroundTask : Added mitigation against tasks attempting to wait for themselves.
 
 1.4.6.0 (relative to 1.4.5.0)
 =======
diff --git a/python/GafferTest/BackgroundTaskTest.py b/python/GafferTest/BackgroundTaskTest.py
index 4c8ccfbf6a2..224866ffa49 100644
--- a/python/GafferTest/BackgroundTaskTest.py
+++ b/python/GafferTest/BackgroundTaskTest.py
@@ -255,5 +255,24 @@ def f( canceller ) :
 		# check for cancellation, and we'll deadlock.
 		del task
 
+	def testSelfWait( self ) :
+
+		def f( canceller ) :
+			# It makes zero sense for a task to wait for itself. Rather than
+			# allow it to deadlock, we want to emit a diagnostic message and
+			# continue.
+			task.wait()
+
+		mh = IECore.CapturingMessageHandler()
+		IECore.MessageHandler.setDefaultHandler( mh )
+
+		task = Gaffer.BackgroundTask( None, f )
+		task.wait()
+
+		self.assertEqual( len( mh.messages ), 1 )
+		self.assertEqual( mh.messages[0].level, IECore.Msg.Level.Error )
+		self.assertEqual( mh.messages[0].context, "BackgroundTask::wait" )
+		self.assertEqual( mh.messages[0].message, "Task attempted to wait for itself" )
+
 if __name__ == "__main__":
 	unittest.main()
diff --git a/src/Gaffer/BackgroundTask.cpp b/src/Gaffer/BackgroundTask.cpp
index 9d88197ed72..c21cc7f99c7 100644
--- a/src/Gaffer/BackgroundTask.cpp
+++ b/src/Gaffer/BackgroundTask.cpp
@@ -50,6 +50,8 @@
 
 #include "fmt/format.h"
 
+#include <thread>
+
 using namespace IECore;
 using namespace Gaffer;
 
@@ -155,9 +157,10 @@ struct BackgroundTask::TaskData : public boost::noncopyable
 
 	Function *function;
 	IECore::Canceller canceller;
-	std::mutex mutex; // Protects `conditionVariable` and `status`
+	std::mutex mutex; // Protects `conditionVariable`, `status` and `threadID`
 	std::condition_variable conditionVariable;
 	Status status;
+	std::thread::id threadId; // Thread that is executing `function`, if any
 };
 
 BackgroundTask::BackgroundTask( const Plug *subject, const Function &function )
@@ -186,6 +189,7 @@ BackgroundTask::BackgroundTask( const Plug *subject, const Function &function )
 			// Otherwise do the work.
 
 			taskData->status = Running;
+			taskData->threadId = std::this_thread::get_id();
 			lock.unlock();
 
 			// Reset thread state rather then inherit the random
@@ -225,6 +229,7 @@ BackgroundTask::BackgroundTask( const Plug *subject, const Function &function )
 
 			lock.lock();
 			taskData->status = status;
+			taskData->threadId = std::thread::id();
 			taskData->conditionVariable.notify_one();
 		}
 	);
@@ -248,6 +253,12 @@ void BackgroundTask::cancel()
 void BackgroundTask::wait()
 {
 	std::unique_lock<std::mutex> lock( m_taskData->mutex );
+	if( m_taskData->threadId == std::this_thread::get_id() )
+	{
+		IECore::msg( IECore::Msg::Error, "BackgroundTask::wait", "Task attempted to wait for itself" );
+		return;
+	}
+
 	m_taskData->conditionVariable.wait(
 		lock,
 		[this]{