diff --git a/poky/meta/classes/pypi.bbclass b/poky/meta/classes/pypi.bbclass
index 87b4c85..384a209 100644
--- a/poky/meta/classes/pypi.bbclass
+++ b/poky/meta/classes/pypi.bbclass
@@ -19,7 +19,7 @@
 
 HOMEPAGE ?= "https://pypi.python.org/pypi/${PYPI_PACKAGE}/"
 SECTION = "devel/python"
-SRC_URI += "${PYPI_SRC_URI}"
+SRC_URI_prepend = "${PYPI_SRC_URI} "
 S = "${WORKDIR}/${PYPI_PACKAGE}-${PV}"
 
 UPSTREAM_CHECK_URI ?= "https://pypi.org/project/${PYPI_PACKAGE}/"