diff --git a/api/server/src/main/java/org/softwareheritage/graph/App.java b/api/server/src/main/java/org/softwareheritage/graph/App.java
index 9f60930..660458a 100644
--- a/api/server/src/main/java/org/softwareheritage/graph/App.java
+++ b/api/server/src/main/java/org/softwareheritage/graph/App.java
@@ -1,54 +1,62 @@
 package org.softwareheritage.graph;
 
 import java.io.IOException;
 import java.util.Optional;
 
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.PropertyNamingStrategy;
 import io.javalin.Javalin;
+import io.javalin.json.JavalinJackson;
 
 import org.softwareheritage.graph.Graph;
 import org.softwareheritage.graph.SwhId;
 import org.softwareheritage.graph.algo.Stats;
 import org.softwareheritage.graph.algo.Visit;
 
 public class App {
   public static void main(String[] args) throws IOException, Exception {
     String path = args[0];
     Graph graph = new Graph(path);
     Stats stats = new Stats(path);
 
     Runtime.getRuntime().addShutdownHook(new Thread() {
       public void run() {
         graph.cleanUp();
       }
     });
 
+    // Configure Jackson JSON properties
+    ObjectMapper objectMapper = JavalinJackson.getObjectMapper();
+    objectMapper.setPropertyNamingStrategy(PropertyNamingStrategy.SNAKE_CASE);
+    JavalinJackson.configure(objectMapper);
+
     Javalin app = Javalin.create().start(5010);
 
     app.get("/stats", ctx -> {
       try {
         ctx.json(stats);
       } catch (Exception e) {
         ctx.status(400);
         ctx.result(e.toString());
       }
     });
 
     app.get("/visit/:swh_id", ctx -> {
       try {
         SwhId start = new SwhId(ctx.pathParam("swh_id"));
 
         // By default, traversal is a forward DFS using all edges
         String algorithm = Optional.ofNullable(ctx.queryParam("traversal")).orElse("dfs");
         String direction = Optional.ofNullable(ctx.queryParam("direction")).orElse("forward");
         String edges = Optional.ofNullable(ctx.queryParam("edges")).orElse("cnt:dir:rel:rev:snp");
 
         ctx.json(new Visit(graph, start, edges, algorithm, direction));
       } catch (IllegalArgumentException e) {
         ctx.status(400);
         ctx.result(e.toString());
       }
     });
 
     app.error(404, ctx -> { ctx.result("Not found"); });
   }
 }