diff --git a/workspace/Dockerfile b/workspace/Dockerfile
index 8d00c47..f90679b 100644
--- a/workspace/Dockerfile
+++ b/workspace/Dockerfile
@@ -50,6 +50,7 @@ ARG UBUNTU_SOURCE
 COPY ./sources.sh /tmp/sources.sh
 
 RUN if [ ${CHANGE_SOURCE} = true ]; then \
+    chmod +x /tmp/sources.sh && \
     /bin/sh -c /tmp/sources.sh && \
     rm -rf /tmp/sources.sh \
 ;fi