diff --git a/controller/handler/badge_test.go b/controller/handler/badge_test.go
index e74bc583..0660280a 100644
--- a/controller/handler/badge_test.go
+++ b/controller/handler/badge_test.go
@@ -94,16 +94,6 @@ func TestUptimeBadge(t *testing.T) {
 			Path:         "/api/v1/endpoints/core_backend/response-times/24h/chart.svg",
 			ExpectedCode: http.StatusOK,
 		},
-		{ // XXX: Remove this in v4.0.0
-			Name:         "backward-compatible-services-badge-uptime-1h",
-			Path:         "/api/v1/services/core_frontend/uptimes/1h/badge.svg",
-			ExpectedCode: http.StatusOK,
-		},
-		{ // XXX: Remove this in v4.0.0
-			Name:         "backward-compatible-services-chart-response-time-24h",
-			Path:         "/api/v1/services/core_backend/response-times/24h/chart.svg",
-			ExpectedCode: http.StatusOK,
-		},
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
diff --git a/controller/handler/chart_test.go b/controller/handler/chart_test.go
index f441ad0c..f15f5e6e 100644
--- a/controller/handler/chart_test.go
+++ b/controller/handler/chart_test.go
@@ -58,11 +58,6 @@ func TestResponseTimeChart(t *testing.T) {
 			Path:         "/api/v1/endpoints/invalid_key/response-times/7d/chart.svg",
 			ExpectedCode: http.StatusNotFound,
 		},
-		{ // XXX: Remove this in v4.0.0
-			Name:         "backward-compatible-services-chart-response-time-24h",
-			Path:         "/api/v1/services/core_backend/response-times/24h/chart.svg",
-			ExpectedCode: http.StatusOK,
-		},
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
diff --git a/controller/handler/endpoint_status_test.go b/controller/handler/endpoint_status_test.go
index 011f53b9..5b0093b8 100644
--- a/controller/handler/endpoint_status_test.go
+++ b/controller/handler/endpoint_status_test.go
@@ -127,11 +127,6 @@ func TestEndpointStatus(t *testing.T) {
 			Path:         "/api/v1/endpoints/invalid_key/statuses",
 			ExpectedCode: http.StatusNotFound,
 		},
-		{ // XXX: Remove this in v4.0.0
-			Name:         "backward-compatible-service-status",
-			Path:         "/api/v1/services/core_frontend/statuses",
-			ExpectedCode: http.StatusOK,
-		},
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
@@ -197,12 +192,6 @@ func TestEndpointStatuses(t *testing.T) {
 			ExpectedCode: http.StatusOK,
 			ExpectedBody: `[{"name":"name","group":"group","key":"group_name","results":[{"status":200,"hostname":"example.org","duration":150000000,"conditionResults":[{"condition":"[STATUS] == 200","success":true},{"condition":"[RESPONSE_TIME] \u003c 500","success":true},{"condition":"[CERTIFICATE_EXPIRATION] \u003c 72h","success":true}],"success":true,"timestamp":"0001-01-01T00:00:00Z"},{"status":200,"hostname":"example.org","duration":750000000,"errors":["error-1","error-2"],"conditionResults":[{"condition":"[STATUS] == 200","success":true},{"condition":"[RESPONSE_TIME] \u003c 500","success":false},{"condition":"[CERTIFICATE_EXPIRATION] \u003c 72h","success":false}],"success":false,"timestamp":"0001-01-01T00:00:00Z"}]}]`,
 		},
-		{ // XXX: Remove this in v4.0.0
-			Name:         "backward-compatible-service-status",
-			Path:         "/api/v1/services/statuses",
-			ExpectedCode: http.StatusOK,
-			ExpectedBody: `[{"name":"name","group":"group","key":"group_name","results":[{"status":200,"hostname":"example.org","duration":150000000,"conditionResults":[{"condition":"[STATUS] == 200","success":true},{"condition":"[RESPONSE_TIME] \u003c 500","success":true},{"condition":"[CERTIFICATE_EXPIRATION] \u003c 72h","success":true}],"success":true,"timestamp":"0001-01-01T00:00:00Z"},{"status":200,"hostname":"example.org","duration":750000000,"errors":["error-1","error-2"],"conditionResults":[{"condition":"[STATUS] == 200","success":true},{"condition":"[RESPONSE_TIME] \u003c 500","success":false},{"condition":"[CERTIFICATE_EXPIRATION] \u003c 72h","success":false}],"success":false,"timestamp":"0001-01-01T00:00:00Z"}]}]`,
-		},
 	}
 
 	for _, scenario := range scenarios {
diff --git a/controller/handler/handler.go b/controller/handler/handler.go
index d496bbd1..c38f6dc1 100644
--- a/controller/handler/handler.go
+++ b/controller/handler/handler.go
@@ -33,18 +33,10 @@ func CreateRouter(staticFolder string, securityConfig *security.Config, uiConfig
 	unprotected.HandleFunc("/v1/endpoints/{key}/uptimes/{duration}/badge.svg", UptimeBadge).Methods("GET")
 	unprotected.HandleFunc("/v1/endpoints/{key}/response-times/{duration}/badge.svg", ResponseTimeBadge).Methods("GET")
 	unprotected.HandleFunc("/v1/endpoints/{key}/response-times/{duration}/chart.svg", ResponseTimeChart).Methods("GET")
-	// XXX: Remove the lines between this and the next XXX comment in v4.0.0
-	protected.HandleFunc("/v1/services/statuses", EndpointStatuses).Methods("GET") // No GzipHandler for this one, because we cache the content as Gzipped already
-	protected.HandleFunc("/v1/services/{key}/statuses", GzipHandlerFunc(EndpointStatus)).Methods("GET")
-	unprotected.HandleFunc("/v1/services/{key}/uptimes/{duration}/badge.svg", UptimeBadge).Methods("GET")
-	unprotected.HandleFunc("/v1/services/{key}/response-times/{duration}/badge.svg", ResponseTimeBadge).Methods("GET")
-	unprotected.HandleFunc("/v1/services/{key}/response-times/{duration}/chart.svg", ResponseTimeChart).Methods("GET")
-	// XXX: Remove the lines between this and the previous XXX comment in v4.0.0
 	// Misc
 	router.Handle("/health", health.Handler().WithJSON(true)).Methods("GET")
 	router.HandleFunc("/favicon.ico", FavIcon(staticFolder)).Methods("GET")
 	// SPA
-	router.HandleFunc("/services/{name}", SinglePageApplication(staticFolder, uiConfig)).Methods("GET") // XXX: Remove this in v4.0.0
 	router.HandleFunc("/endpoints/{name}", SinglePageApplication(staticFolder, uiConfig)).Methods("GET")
 	router.HandleFunc("/", SinglePageApplication(staticFolder, uiConfig)).Methods("GET")
 	// Everything else falls back on static content
diff --git a/controller/handler/spa_test.go b/controller/handler/spa_test.go
index 20838f7e..7d968fa8 100644
--- a/controller/handler/spa_test.go
+++ b/controller/handler/spa_test.go
@@ -48,11 +48,6 @@ func TestSinglePageApplication(t *testing.T) {
 			Path:         "/endpoints/core_frontend",
 			ExpectedCode: http.StatusOK,
 		},
-		{ // XXX: Remove this in v4.0.0
-			Name:         "frontend-service",
-			Path:         "/services/core_frontend",
-			ExpectedCode: http.StatusOK,
-		},
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
diff --git a/storage/store/store_test.go b/storage/store/store_test.go
index e2828dc4..aa561ca4 100644
--- a/storage/store/store_test.go
+++ b/storage/store/store_test.go
@@ -579,11 +579,6 @@ func TestInitialize(t *testing.T) {
 			Cfg:         &storage.Config{Type: storage.TypeMemory},
 			ExpectedErr: nil,
 		},
-		{ // XXX: Remove for v4.0.0. See https://github.com/TwiN/gatus/issues/198
-			Name:        "memory-with-path",
-			Cfg:         &storage.Config{Type: storage.TypeMemory, Path: t.TempDir() + "/TestInitialize_memory-with-path.db"},
-			ExpectedErr: nil,
-		},
 		{
 			Name:        "sqlite-no-path",
 			Cfg:         &storage.Config{Type: storage.TypeSQLite},
diff --git a/web/app/src/router/index.js b/web/app/src/router/index.js
index e525d7a8..b04bbd87 100644
--- a/web/app/src/router/index.js
+++ b/web/app/src/router/index.js
@@ -13,10 +13,6 @@ const routes = [
         name: 'Details',
         component: Details,
     },
-    { // XXX: Remove in v4.0.0
-        path: '/services/:key',
-        redirect: {name: 'Details'}
-    },
 ];
 
 const router = createRouter({