diff --git a/.github/workflows/linux.yaml b/.github/workflows/linux.yaml
index c6a6c83d..9e1952f1 100644
--- a/.github/workflows/linux.yaml
+++ b/.github/workflows/linux.yaml
@@ -65,7 +65,7 @@ jobs:
   ubuntu:
     strategy:
       matrix:
-        ubuntu_version: [ubuntu-18.04, ubuntu-20.04, ubuntu-22.04]
+        ubuntu_version: [ubuntu-20.04, ubuntu-22.04]
         compiler: [clang, gcc]
     runs-on: ${{ matrix.ubuntu_version }}
     steps:
diff --git a/Docker.autogen b/Docker.autogen
index 44ece764..5ce77dd0 100644
--- a/Docker.autogen
+++ b/Docker.autogen
@@ -1,6 +1,6 @@
-FROM ubuntu:18.04
-RUN apt-get update && \
-	apt-get install -qy \
+FROM ubuntu:20.04
+RUN apt update && \
+	apt install -qy \
 		autoconf \
 		automake \
 		gettext \