diff --git a/.github/workflows/continuous-integration.yml b/.github/workflows/continuous-integration.yml
index 71d2380..196ba32 100644
--- a/.github/workflows/continuous-integration.yml
+++ b/.github/workflows/continuous-integration.yml
@@ -13,7 +13,7 @@ jobs:
 
     services:
       postgres:
-        image: postgres:16-alpine
+        image: postgres:18-alpine@sha256:9a8afca54e7861fd90fab5fdf4c42477a6b1cb7d293595148e674e0a3181de15
         env:
           POSTGRES_DB: constraint_engine_test
           POSTGRES_USER: app
diff --git a/compose.yaml b/compose.yaml
index 106f553..66c0d1c 100644
--- a/compose.yaml
+++ b/compose.yaml
@@ -31,7 +31,7 @@ services:
     restart: unless-stopped
 
   db:
-    image: postgres:16-alpine
+    image: postgres:18-alpine@sha256:9a8afca54e7861fd90fab5fdf4c42477a6b1cb7d293595148e674e0a3181de15
     environment:
       POSTGRES_DB: constraint_engine
       POSTGRES_USER: ${DB_USER:-app}