diff --git a/Dockerfile b/Dockerfile
index d5e644e8..9a75ade0 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -174,6 +174,7 @@ ENV SOURCEBOT_PUBLIC_KEY_PATH=/app/public.pem
 # Note that this key does not need to be kept secret, so it's not
 # necessary to use Docker build secrets here.
 # @see: https://posthog.com/tutorials/api-capture-events#authenticating-with-the-project-api-key
+# @note: this is also declared in the shared env.server.ts file.
 ENV POSTHOG_PAPIK=phc_lLPuFFi5LH6c94eFJcqvYVFwiJffVcV6HD8U4a1OnRW
 
 # Valid values are: debug, info, warn, error
diff --git a/packages/shared/src/env.server.ts b/packages/shared/src/env.server.ts
index 21c08563..66e27c31 100644
--- a/packages/shared/src/env.server.ts
+++ b/packages/shared/src/env.server.ts
@@ -120,7 +120,8 @@ export const env = createEnv({
         CONFIG_MAX_REPOS_NO_TOKEN: numberSchema.default(Number.MAX_SAFE_INTEGER),
         NODE_ENV: z.enum(["development", "test", "production"]),
         SOURCEBOT_TELEMETRY_DISABLED: booleanSchema.default('false'),
-        POSTHOG_PAPIK: z.string(),
+        // @note: this is also declared in the Dockerfile.
+        POSTHOG_PAPIK: z.string().default("phc_lLPuFFi5LH6c94eFJcqvYVFwiJffVcV6HD8U4a1OnRW"),
 
         // Database variables
         // Either DATABASE_URL or DATABASE_HOST, DATABASE_USERNAME, DATABASE_PASSWORD, and DATABASE_NAME must be set.