diff --git a/cmd/server/tests/processing_issues_test.go b/cmd/server/tests/processing_issues_test.go
index 03351c8..5ad26b7 100644
--- a/cmd/server/tests/processing_issues_test.go
+++ b/cmd/server/tests/processing_issues_test.go
@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"net/http"
 	"net/http/httptest"
+	"net/url"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -108,8 +109,8 @@ func TestProcessingIssuesListInputValidation(t *testing.T) {
 		{
 			name:           "Empty UUID",
 			libraryID:      "",
-			expectedStatus: http.StatusNotFound,
-			description:    "Should return 404 for empty ID",
+			expectedStatus: http.StatusBadRequest,
+			description:    "Should return 400 for empty ID",
 		},
 		{
 			name:           "UUID with extra path traversal",
@@ -139,7 +140,7 @@ func TestProcessingIssuesListInputValidation(t *testing.T) {
 
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {
-			req := httptest.NewRequest("GET", "/api/libraries/"+tc.libraryID+"/issues/list", nil)
+			req := httptest.NewRequest("GET", "/api/libraries/"+url.PathEscape(tc.libraryID)+"/issues/list", nil)
 			req.Header.Set("Authorization", "Bearer "+token)
 			rec := httptest.NewRecorder()
 
@@ -284,8 +285,8 @@ func TestProcessingIssueStatsInputValidation(t *testing.T) {
 		{
 			name:           "Empty UUID",
 			libraryID:      "",
-			expectedStatus: http.StatusNotFound,
-			description:    "Should return 404 for empty ID",
+			expectedStatus: http.StatusBadRequest,
+			description:    "Should return 400 for empty ID",
 		},
 		{
 			name:           "UUID with extra path traversal",
@@ -315,7 +316,7 @@ func TestProcessingIssueStatsInputValidation(t *testing.T) {
 
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {
-			req := httptest.NewRequest("GET", "/api/libraries/"+tc.libraryID+"/issues/stats", nil)
+			req := httptest.NewRequest("GET", "/api/libraries/"+url.PathEscape(tc.libraryID)+"/issues/stats", nil)
 			req.Header.Set("Authorization", "Bearer "+token)
 			rec := httptest.NewRecorder()
 
@@ -426,7 +427,6 @@ func TestProcessingIssuesDifferentLibraryTypes(t *testing.T) {
 		{"Ebooks library", "ebooks"},
 		{"Comics library", "comics"},
 		{"Manga library", "manga"},
-		{"Audiobooks library", "audiobooks"},
 	}
 
 	for _, lt := range libraryTypes {