diff --git a/Makefile b/Makefile
index 614d3cd776bcdb59a6e4f6bc2705e6b4de9a8c69..3e8701a05d08e879f9092e41f485664426709adf 100644
--- a/Makefile
+++ b/Makefile
@@ -10,7 +10,7 @@ COVER_PACKAGES=hbp_nrp_distributed_nest
 #documentation to build
 #DOC_MODULES=hbp_nrp_distributed_nest/doc
 
-PYTHON_PIP_VERSION?='pip>=19'
+PYTHON_PIP_VERSION?=pip>=19
 
 ##### DO NOT MODIFY BELOW #####################