diff --git a/jwt/login.go b/jwt/login.go
index 1090cd3..0494e44 100644
--- a/jwt/login.go
+++ b/jwt/login.go
@@ -51,7 +51,7 @@ var (
 )
 
 // VerifyToken verifys a given string-token.
-func (tv *TokenVerifier) VerifyToken(tokenString string) (budgeteer.Token, error) {
+func (tv *TokenVerifier) VerifyToken(tokenString string) (budgeteer.Token, error) { //nolint:ireturn
 	token, err := jwt.Parse(tokenString, func(token *jwt.Token) (interface{}, error) {
 		if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
 			return nil, fmt.Errorf("method '%v': %w", token.Header["alg"], ErrUnexpectedSigningMethod)
diff --git a/postgres/budgetservice.go b/postgres/budgetservice.go
index bcb4512..82372dd 100644
--- a/postgres/budgetservice.go
+++ b/postgres/budgetservice.go
@@ -8,7 +8,7 @@ import (
 	"github.com/google/uuid"
 )
 
-// NewBudget creates a budget and adds it to the current user
+// NewBudget creates a budget and adds it to the current user.
 func (s *Database) NewBudget(context context.Context, name string, userID uuid.UUID) (*Budget, error) {
 	tx, err := s.BeginTx(context, &sql.TxOptions{})
 	if err != nil {
diff --git a/postgres/conn.go b/postgres/conn.go
index 6a5c814..6c04480 100644
--- a/postgres/conn.go
+++ b/postgres/conn.go
@@ -17,7 +17,7 @@ type Database struct {
 	*sql.DB
 }
 
-// Connect to a database
+// Connect connects to a database.
 func Connect(typ string, connString string) (*Database, error) {
 	conn, err := sql.Open(typ, connString)
 	if err != nil {
diff --git a/postgres/ynab-import.go b/postgres/ynab-import.go
index 8892d8f..3c80bad 100644
--- a/postgres/ynab-import.go
+++ b/postgres/ynab-import.go
@@ -56,7 +56,7 @@ func NewYNABImport(context context.Context, queries *Queries, budgetID uuid.UUID
 // "Month"	"Category Group/Category"	"Category Group"	"Category"	"Budgeted"	"Activity"	"Available"
 // "Apr 2019"	"Income: Next Month"	"Income"	"Next Month"	0,00€	0,00€	0,00€
 //
-// Activity and Available are not imported, since they are determined by the transactions and historic assignments
+// Activity and Available are not imported, since they are determined by the transactions and historic assignments.
 func (ynab *YNABImport) ImportAssignments(context context.Context, r io.Reader) error {
 	csv := csv.NewReader(r)
 	csv.Comma = '\t'
@@ -184,7 +184,8 @@ func (ynab *YNABImport) ImportTransactions(context context.Context, r io.Reader)
 		// Transaction is a transfer to
 		var shouldReturn bool
 		var returnValue error
-		openTransfers, shouldReturn, returnValue = ynab.ImportTransaction(payeeName, context, transaction, accountName, openTransfers, account, amount)
+		openTransfers, shouldReturn, returnValue = ynab.ImportTransaction(
+			payeeName, context, transaction, accountName, openTransfers, account, amount)
 		if shouldReturn {
 			return returnValue
 		}
@@ -368,13 +369,15 @@ func (ynab *YNABImport) GetCategory(context context.Context, group string, name
 		}
 	}
 
-	categoryGroup, err := ynab.queries.CreateCategoryGroup(context, CreateCategoryGroupParams{Name: group, BudgetID: ynab.budgetID})
+	newGroup := CreateCategoryGroupParams{Name: group, BudgetID: ynab.budgetID}
+	categoryGroup, err := ynab.queries.CreateCategoryGroup(context, newGroup)
 	if err != nil {
 		return uuid.NullUUID{}, err
 	}
 	ynab.categoryGroups = append(ynab.categoryGroups, categoryGroup)
 
-	category, err := ynab.queries.CreateCategory(context, CreateCategoryParams{Name: name, CategoryGroupID: categoryGroup.ID})
+	newCategory := CreateCategoryParams{Name: name, CategoryGroupID: categoryGroup.ID}
+	category, err := ynab.queries.CreateCategory(context, newCategory)
 	if err != nil {
 		return uuid.NullUUID{}, err
 	}
diff --git a/server/account_test.go b/server/account_test.go
index d7ee98e..8ea523a 100644
--- a/server/account_test.go
+++ b/server/account_test.go
@@ -14,7 +14,7 @@ import (
 	"github.com/gin-gonic/gin"
 )
 
-func init() {
+func init() { //nolint:gochecknoinits
 	txdb.Register("pgtx", "pgx", "postgres://budgeteer_test:budgeteer_test@localhost:5432/budgeteer_test")
 }
 
diff --git a/server/autocomplete.go b/server/autocomplete.go
index 626b9ee..46dfb3c 100644
--- a/server/autocomplete.go
+++ b/server/autocomplete.go
@@ -1,7 +1,6 @@
 package server
 
 import (
-	"fmt"
 	"net/http"
 
 	"git.javil.eu/jacob1123/budgeteer/postgres"
@@ -13,7 +12,7 @@ func (h *Handler) autocompleteCategories(c *gin.Context) {
 	budgetID := c.Param("budgetid")
 	budgetUUID, err := uuid.Parse(budgetID)
 	if err != nil {
-		c.AbortWithError(http.StatusBadRequest, fmt.Errorf("budgetid missing from URL"))
+		c.AbortWithStatusJSON(http.StatusBadRequest, ErrorResponse{"budgetid missing from URL"})
 		return
 	}
 
@@ -35,7 +34,7 @@ func (h *Handler) autocompletePayee(c *gin.Context) {
 	budgetID := c.Param("budgetid")
 	budgetUUID, err := uuid.Parse(budgetID)
 	if err != nil {
-		c.AbortWithError(http.StatusBadRequest, fmt.Errorf("budgetid missing from URL"))
+		c.AbortWithStatusJSON(http.StatusBadRequest, ErrorResponse{"budgetid missing from URL"})
 		return
 	}
 
diff --git a/server/budget.go b/server/budget.go
index e330659..dd66e43 100644
--- a/server/budget.go
+++ b/server/budget.go
@@ -1,7 +1,6 @@
 package server
 
 import (
-	"fmt"
 	"net/http"
 
 	"git.javil.eu/jacob1123/budgeteer"
@@ -20,7 +19,7 @@ func (h *Handler) newBudget(c *gin.Context) {
 	}
 
 	if newBudget.Name == "" {
-		c.AbortWithError(http.StatusNotAcceptable, fmt.Errorf("Budget name is needed"))
+		c.AbortWithStatusJSON(http.StatusBadRequest, ErrorResponse{"budget name is required"})
 		return
 	}
 
diff --git a/server/budgeting.go b/server/budgeting.go
index 48ff479..6addb2e 100644
--- a/server/budgeting.go
+++ b/server/budgeting.go
@@ -85,7 +85,8 @@ func (h *Handler) budgetingForMonth(c *gin.Context) {
 	}
 
 	// skip everything in the future
-	categoriesWithBalance, moneyUsed, err := h.calculateBalances(c, budget, firstOfNextMonth, firstOfMonth, categories, cumultativeBalances)
+	categoriesWithBalance, moneyUsed, err := h.calculateBalances(
+		c, budget, firstOfNextMonth, firstOfMonth, categories, cumultativeBalances)
 	if err != nil {
 		return
 	}
diff --git a/server/http.go b/server/http.go
index bdc8d66..569464b 100644
--- a/server/http.go
+++ b/server/http.go
@@ -104,7 +104,11 @@ func (h *Handler) ServeStaticFile(c *gin.Context, fullPath string) {
 		return
 	}
 
-	http.ServeContent(c.Writer, c.Request, stat.Name(), stat.ModTime(), file.(io.ReadSeeker))
+	if file, ok := file.(io.ReadSeeker); ok {
+		http.ServeContent(c.Writer, c.Request, stat.Name(), stat.ModTime(), file)
+	} else {
+		panic("File does not implement ReadSeeker")
+	}
 }
 
 func enableCachingForStaticFiles() gin.HandlerFunc {
diff --git a/server/transaction.go b/server/transaction.go
index c11afdb..36e6380 100644
--- a/server/transaction.go
+++ b/server/transaction.go
@@ -50,7 +50,7 @@ func (h *Handler) newTransaction(c *gin.Context) {
 	}*/
 
 	// if !transactionUUID.Valid {
-	new := postgres.CreateTransactionParams{
+	newTransaction := postgres.CreateTransactionParams{
 		Memo:       payload.Memo,
 		Date:       time.Time(payload.Date),
 		Amount:     amount,
@@ -59,7 +59,7 @@ func (h *Handler) newTransaction(c *gin.Context) {
 		CategoryID: payload.Category.ID, // TODO handle new category
 		Status:     postgres.TransactionStatus(payload.State),
 	}
-	_, err = h.Service.CreateTransaction(c.Request.Context(), new)
+	_, err = h.Service.CreateTransaction(c.Request.Context(), newTransaction)
 	if err != nil {
 		c.AbortWithError(http.StatusInternalServerError, fmt.Errorf("create transaction: %w", err))
 	}