diff --git a/src/routes/categories.ts b/src/routes/categories.ts
index 9f9176f..9c37085 100644
--- a/src/routes/categories.ts
+++ b/src/routes/categories.ts
@@ -12,5 +12,11 @@ export default async function categories(fastify: FastifyInstance) {
     // get the category by provided id
     fastify.get<{
         Params: CategoryParams
-    }>('/categories/:id', async (req) => RECIPE_CATEGORIES.find(recipeCategory => recipeCategory.id === parseInt(req.params.id)))
+    }>('/categories/:id', async (req, reply) => {
+        const recipeCategory = RECIPE_CATEGORIES.find(recipeCategory => recipeCategory.id === parseInt(req.params.id))
+        if(!recipeCategory) {
+            reply.code(404).type('text/html').send('Not Found')
+        }
+        return recipeCategory
+    })
 }
diff --git a/src/routes/recipes.ts b/src/routes/recipes.ts
index c1628f5..a397f4a 100644
--- a/src/routes/recipes.ts
+++ b/src/routes/recipes.ts
@@ -35,5 +35,11 @@ export default async function recipes(fastify: FastifyInstance) {
     // get the recipe by provided id
     fastify.get<{
         Params: RecipeParams
-    }>('/recipes/:id', async (req) => RECIPES.find(recipe => recipe.id === parseInt(req.params.id)))
+    }>('/recipes/:id', async (req, reply) => {
+        const recipe = RECIPES.find(recipe => recipe.id === parseInt(req.params.id))
+        if(!recipe) {
+            reply.code(404).type('text/html').send('Not Found')
+        }
+        return recipe
+    })
 }
diff --git a/src/routes/users.ts b/src/routes/users.ts
index c24ffd8..819b86e 100644
--- a/src/routes/users.ts
+++ b/src/routes/users.ts
@@ -12,5 +12,11 @@ export default async function users(fastify: FastifyInstance) {
     // get the user by provided id
     fastify.get<{
         Params: UserParams
-    }>('/users/:id', async (req) => USERS.find(user => user.id === parseInt(req.params.id)))
+    }>('/users/:id', async (req, reply) => {
+        const user = USERS.find(user => user.id === parseInt(req.params.id))
+        if(!user) {
+            reply.code(404).type('text/html').send('Not Found')
+        }
+        return user
+    })
 }