diff --git a/dockerfiles/swh-deposit/Dockerfile b/dockerfiles/swh-deposit/Dockerfile
--- a/dockerfiles/swh-deposit/Dockerfile
+++ b/dockerfiles/swh-deposit/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3
+FROM python:3.6
 
 RUN export DEBIAN_FRONTEND=noninteractive && \
   apt-get update && apt-get upgrade -y && \
diff --git a/dockerfiles/swh-indexer-journal-client/Dockerfile b/dockerfiles/swh-indexer-journal-client/Dockerfile
--- a/dockerfiles/swh-indexer-journal-client/Dockerfile
+++ b/dockerfiles/swh-indexer-journal-client/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3
+FROM python:3.6
 
 RUN export DEBIAN_FRONTEND=noninteractive && \
   apt-get update && \
diff --git a/dockerfiles/swh-indexer-storage/Dockerfile b/dockerfiles/swh-indexer-storage/Dockerfile
--- a/dockerfiles/swh-indexer-storage/Dockerfile
+++ b/dockerfiles/swh-indexer-storage/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3
+FROM python:3.6
 
 RUN export DEBIAN_FRONTEND=noninteractive && \
   apt-get update && \
diff --git a/dockerfiles/swh-indexer-worker/Dockerfile b/dockerfiles/swh-indexer-worker/Dockerfile
--- a/dockerfiles/swh-indexer-worker/Dockerfile
+++ b/dockerfiles/swh-indexer-worker/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3
+FROM python:3.6
 
 RUN export DEBIAN_FRONTEND=noninteractive && \
   apt-get update && \
diff --git a/dockerfiles/swh-journal-client/Dockerfile b/dockerfiles/swh-journal-client/Dockerfile
--- a/dockerfiles/swh-journal-client/Dockerfile
+++ b/dockerfiles/swh-journal-client/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3
+FROM python:3.6
 
 RUN export DEBIAN_FRONTEND=noninteractive && \
   apt-get update && \
diff --git a/dockerfiles/swh-journal-publisher/Dockerfile b/dockerfiles/swh-journal-publisher/Dockerfile
--- a/dockerfiles/swh-journal-publisher/Dockerfile
+++ b/dockerfiles/swh-journal-publisher/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3
+FROM python:3.6
 
 RUN export DEBIAN_FRONTEND=noninteractive && \
   apt-get update && \
diff --git a/dockerfiles/swh-listers-worker/Dockerfile b/dockerfiles/swh-listers-worker/Dockerfile
--- a/dockerfiles/swh-listers-worker/Dockerfile
+++ b/dockerfiles/swh-listers-worker/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3
+FROM python:3.6
 
 RUN export DEBIAN_FRONTEND=noninteractive && \
   apt-get update && \
diff --git a/dockerfiles/swh-loaders-worker/Dockerfile b/dockerfiles/swh-loaders-worker/Dockerfile
--- a/dockerfiles/swh-loaders-worker/Dockerfile
+++ b/dockerfiles/swh-loaders-worker/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3
+FROM python:3.6
 
 RUN export DEBIAN_FRONTEND=noninteractive && \
   apt-get update && \
diff --git a/dockerfiles/swh-objstorage/Dockerfile b/dockerfiles/swh-objstorage/Dockerfile
--- a/dockerfiles/swh-objstorage/Dockerfile
+++ b/dockerfiles/swh-objstorage/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3
+FROM python:3.6
 
 RUN export DEBIAN_FRONTEND=noninteractive && \
   apt-get update && \
diff --git a/dockerfiles/swh-scheduler-api/Dockerfile b/dockerfiles/swh-scheduler-api/Dockerfile
--- a/dockerfiles/swh-scheduler-api/Dockerfile
+++ b/dockerfiles/swh-scheduler-api/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3
+FROM python:3.6
 
 RUN export DEBIAN_FRONTEND=noninteractive && \
   apt-get update && \
diff --git a/dockerfiles/swh-scheduler-worker/Dockerfile b/dockerfiles/swh-scheduler-worker/Dockerfile
--- a/dockerfiles/swh-scheduler-worker/Dockerfile
+++ b/dockerfiles/swh-scheduler-worker/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3
+FROM python:3.6
 
 RUN export DEBIAN_FRONTEND=noninteractive && \
   apt-get update && \
diff --git a/dockerfiles/swh-storage-listener/Dockerfile b/dockerfiles/swh-storage-listener/Dockerfile
--- a/dockerfiles/swh-storage-listener/Dockerfile
+++ b/dockerfiles/swh-storage-listener/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3
+FROM python:3.6
 
 RUN export DEBIAN_FRONTEND=noninteractive && \
   apt-get update && \
diff --git a/dockerfiles/swh-storage/Dockerfile b/dockerfiles/swh-storage/Dockerfile
--- a/dockerfiles/swh-storage/Dockerfile
+++ b/dockerfiles/swh-storage/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3
+FROM python:3.6
 
 RUN export DEBIAN_FRONTEND=noninteractive && \
   apt-get update && \
diff --git a/dockerfiles/swh-web/Dockerfile b/dockerfiles/swh-web/Dockerfile
--- a/dockerfiles/swh-web/Dockerfile
+++ b/dockerfiles/swh-web/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3
+FROM python:3.6
 
 RUN export DEBIAN_FRONTEND=noninteractive && \
   apt-get update && apt-get upgrade -y && \