diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 0f97ad90e44c231ac3a597210618422a89a8f5ec..fd3596aa8912e56e8ef1ba53f414d5467f422632 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -5,7 +5,6 @@ test_build_image:
   services:
   - docker:dind
   script:
-    - docker build 3.5
     - docker build 3.6
     - docker build 3.7
     - docker build 3.8
@@ -30,11 +29,6 @@ test_build_image:
   only:
     - tags
 
-build_3_5:
-  extends: .build_image
-  variables:
-    PYTHON_VERSION: "3.5"
-
 build_3_6:
   extends: .build_image
   variables:
diff --git a/3.5/Dockerfile b/3.5/Dockerfile
deleted file mode 100644
index 1dd4c1c93a0bfd9acef5c1c558c8e3b2504c0b74..0000000000000000000000000000000000000000
--- a/3.5/Dockerfile
+++ /dev/null
@@ -1,9 +0,0 @@
-FROM python:3.5-slim-buster
-
-# Install libsodium
-RUN apt update && \
-apt install --yes libsodium23 make && \
-rm -rf /var/lib/apt/lists
-
-# Install Poetry
-RUN pip3 install poetry