diff --git a/php7.3/Dockerfile b/php7.3/Dockerfile
index b2928f4..382f15e 100644
--- a/php7.3/Dockerfile
+++ b/php7.3/Dockerfile
@@ -1,4 +1,4 @@
-FROM debian:buster
+FROM debian:bookworm
 
 # install the PHP extensions we need
 # see https://friendi.ca/resources/requirements/
diff --git a/php7.4/Dockerfile b/php7.4/Dockerfile
index 2741f8f..2f53805 100644
--- a/php7.4/Dockerfile
+++ b/php7.4/Dockerfile
@@ -1,4 +1,4 @@
-FROM debian:buster
+FROM debian:bookworm
 
 # install the PHP extensions we need
 # see https://friendi.ca/resources/requirements/
diff --git a/php8.0/Dockerfile b/php8.0/Dockerfile
index 15aa569..2f230d4 100644
--- a/php8.0/Dockerfile
+++ b/php8.0/Dockerfile
@@ -1,4 +1,4 @@
-FROM debian:buster
+FROM debian:bookworm
 
 # install the PHP extensions we need
 # see https://friendi.ca/resources/requirements/
diff --git a/php8.1/Dockerfile b/php8.1/Dockerfile
index fa40766..6bf4524 100644
--- a/php8.1/Dockerfile
+++ b/php8.1/Dockerfile
@@ -1,4 +1,4 @@
-FROM debian:buster
+FROM debian:bookworm
 
 # install the PHP extensions we need
 # see https://friendi.ca/resources/requirements/
diff --git a/php8.2/Dockerfile b/php8.2/Dockerfile
index 056146e..ef9d3f6 100644
--- a/php8.2/Dockerfile
+++ b/php8.2/Dockerfile
@@ -1,4 +1,4 @@
-FROM debian:buster
+FROM debian:bookworm
 
 # install the PHP extensions we need
 # see https://friendi.ca/resources/requirements/