diff --git a/amqp1-requirements.txt b/amqp1-requirements.txt
index f5d6af0ac..971b32910 100644
--- a/amqp1-requirements.txt
+++ b/amqp1-requirements.txt
@@ -1,3 +1,3 @@
 # AMQP 1.0 support depends on the Qpid Proton AMQP 1.0
 # development libraries.
-pyngus>=1.3.1  # Apache-2.0
+pyngus>=1.3.1;python_version=='2.7'  # Apache-2.0