diff --git a/3.0/Dockerfile b/3.0/Dockerfile
index 54b6daa..35e5b54 100644
--- a/3.0/Dockerfile
+++ b/3.0/Dockerfile
@@ -14,8 +14,8 @@ ENV QEMU_KEYS \
 
 # https://www.qemu.org/download/#source
 # https://download.qemu.org/?C=M;O=D
-ENV QEMU_VERSION 3.0.0
-ENV QEMU_URL https://download.qemu.org/qemu-3.0.0.tar.xz
+ENV QEMU_VERSION 3.0.1
+ENV QEMU_URL https://download.qemu.org/qemu-3.0.1.tar.xz
 
 RUN set -eux; \
 	\
diff --git a/2.11/Dockerfile b/4.0/Dockerfile
similarity index 97%
rename from 2.11/Dockerfile
rename to 4.0/Dockerfile
index efab59c..5af0c3d 100644
--- a/2.11/Dockerfile
+++ b/4.0/Dockerfile
@@ -14,8 +14,8 @@ ENV QEMU_KEYS \
 
 # https://www.qemu.org/download/#source
 # https://download.qemu.org/?C=M;O=D
-ENV QEMU_VERSION 2.11.2
-ENV QEMU_URL https://download.qemu.org/qemu-2.11.2.tar.xz
+ENV QEMU_VERSION 4.0.0
+ENV QEMU_URL https://download.qemu.org/qemu-4.0.0.tar.xz
 
 RUN set -eux; \
 	\
diff --git a/2.11/qemu-signals.patch b/4.0/qemu-signals.patch
similarity index 100%
rename from 2.11/qemu-signals.patch
rename to 4.0/qemu-signals.patch
diff --git a/2.11/start-qemu b/4.0/start-qemu
similarity index 100%
rename from 2.11/start-qemu
rename to 4.0/start-qemu
diff --git a/generate-stackbrew-library.sh b/generate-stackbrew-library.sh
index dc0fae1..e445b24 100755
--- a/generate-stackbrew-library.sh
+++ b/generate-stackbrew-library.sh
@@ -2,7 +2,8 @@
 set -Eeuo pipefail
 
 declare -A aliases=(
-	[3.1]='3 latest'
+	[4.0]='4 latest'
+	[3.1]='3'
 	[2.12]='2'
 )