diff --git a/Dockerfile b/Dockerfile
index e0dd02c..81fd0bf 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,6 +1,6 @@
 FROM ruby:alpine
 
-RUN apk add make gcc libc-dev
+RUN apk add make gcc libc-dev libpq-dev
 
 WORKDIR /app
 ADD gems.rb gems.locked ./
diff --git a/gems.locked b/gems.locked
index 6fa5e90..8e439cc 100644
--- a/gems.locked
+++ b/gems.locked
@@ -18,6 +18,7 @@ GEM
     mustermann (3.0.0)
       ruby2_keywords (~> 0.0.1)
     nio4r (2.5.9)
+    pg (1.5.3)
     puma (6.3.0)
       nio4r (~> 2.0)
     rack (2.2.7)
@@ -39,6 +40,7 @@ PLATFORMS
 
 DEPENDENCIES
   activerecord
+  pg
   puma
   sinatra
   sqlite3
diff --git a/gems.rb b/gems.rb
index 0e6828b..f4e63ff 100644
--- a/gems.rb
+++ b/gems.rb
@@ -7,3 +7,4 @@ gem 'activerecord'
 gem 'puma'
 gem 'sinatra'
 gem 'sqlite3'
+gem 'pg'