diff --git a/apps/web/apollo/client.js b/apps/web/apollo/client.js
index cb3b5fd..442f4cd 100644
--- a/apps/web/apollo/client.js
+++ b/apps/web/apollo/client.js
@@ -14,6 +14,10 @@ function createApolloClient(headers) {
 }
 
 export default function initializeApollo(initialState, headers) {
+  if (isServer() && !headers) {
+    throw new Error('initializeApollo: headers must be provided in server side');
+  }
+
   const _apolloClient = apolloClient ?? createApolloClient(headers);
 
   // If your page has Next.js data fetching methods that use Apollo Client, the initial state
diff --git a/apps/web/server/routers/elt/kasko.ts b/apps/web/server/routers/elt/kasko.ts
index ec6ace9..d255a7c 100644
--- a/apps/web/server/routers/elt/kasko.ts
+++ b/apps/web/server/routers/elt/kasko.ts
@@ -13,9 +13,9 @@ export const eltKaskoRouter = router({
   eltKasko: protectedProcedure
     .input(EltInputSchema)
     .output(EltOutputSchema)
-    .mutation(async ({ input }) => {
+    .mutation(async ({ input, ctx }) => {
       try {
-        const apolloClient = initializeApollo();
+        const apolloClient = initializeApollo(null, ctx.headers);
         const store = new RootStore();
         store.$calculation.$values.hydrate(input.calculation.values);
 
diff --git a/apps/web/server/routers/elt/osago.ts b/apps/web/server/routers/elt/osago.ts
index 48f69c8..04c804c 100644
--- a/apps/web/server/routers/elt/osago.ts
+++ b/apps/web/server/routers/elt/osago.ts
@@ -13,9 +13,9 @@ export const eltOsagoRouter = router({
   eltOsago: protectedProcedure
     .input(EltInputSchema)
     .output(EltOutputSchema)
-    .mutation(async ({ input }) => {
+    .mutation(async ({ input, ctx }) => {
       try {
-        const apolloClient = initializeApollo();
+        const apolloClient = initializeApollo(null, ctx.headers);
         const store = new RootStore();
         store.$calculation.$values.hydrate(input.calculation.values);