diff --git a/docker-compose/sdptr-sim/Dockerfile b/docker-compose/sdptr-sim/Dockerfile
index 89ccb9e964c890ceff8a92adef8ecd5e0d16b4a5..ed6ac8d35059fda67231a0dc17c71c3a5983b13c 100644
--- a/docker-compose/sdptr-sim/Dockerfile
+++ b/docker-compose/sdptr-sim/Dockerfile
@@ -9,7 +9,6 @@ RUN apt-get update && \
     apt-get clean
 
 # Install SDPTR
-ENV A=A
 RUN cd / && git clone --depth 1 --branch master https://git.astron.nl/lofar2.0/sdptr
 
 RUN cd /sdptr && \