diff --git a/base/omgsim:4.10.01 b/base/omgsim:4.10.01
index 989377ccb13c00f7d62a8df878dd0ee12fc2a268..0d37dd14f5a99888340e88bb6231f06dcde6b9c0 100644
--- a/base/omgsim:4.10.01
+++ b/base/omgsim:4.10.01
@@ -8,7 +8,7 @@ FROM docker.km3net.de/base/centos-full:7
 
 # get devtoolset from this repo
  RUN yum install -y devtoolset-4-gcc* devtoolset-4-gcc-gfortran devtoolset-4-binutils
- . /opt/rh/devtoolset-4/enable
+ RUN . /opt/rh/devtoolset-4/enable
 
 # create folder for additional non-standard CentOS7 software
  RUN mkdir $HOME/OMGsim