diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index 67364dee..78232298 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -5,15 +5,16 @@ vaadin8 = "8.16.1"
 # This is the latest stable Vaadin 14 version
 vaadin14 = "14.10.12"
 # Latest unstable Vaadin 14 version
-vaadin14_next = "14.11.9"
-vaadin23="23.2.17"
-vaadin23_next="23.3.34"
+vaadin14_next = "14.11.10"
+vaadin23="23.3.35"
+# Don't go 23.5+ - it requires license
+vaadin23_next="23.4.1"
 # https://repo1.maven.org/maven2/org/slf4j/slf4j-api/
-slf4j = "2.0.12"
+slf4j = "2.0.13"
 # Stay on 1.0.8/1.1.3 because of Vaadin 8 compatibility
 karibudsl10 = "1.0.8"
 karibudsl11 = "1.1.3"
-fake-servlet = "1.0"
+fake-servlet = "1.1"
 karibu_tools = "0.14"
 junit = "5.10.2"
 
diff --git a/karibu-testing-v10/kt10-tests/src/main/kotlin/com/github/mvysny/kaributesting/v10/MockVaadinTest.kt b/karibu-testing-v10/kt10-tests/src/main/kotlin/com/github/mvysny/kaributesting/v10/MockVaadinTest.kt
index cd5378ae..c1ad8483 100644
--- a/karibu-testing-v10/kt10-tests/src/main/kotlin/com/github/mvysny/kaributesting/v10/MockVaadinTest.kt
+++ b/karibu-testing-v10/kt10-tests/src/main/kotlin/com/github/mvysny/kaributesting/v10/MockVaadinTest.kt
@@ -14,6 +14,8 @@ import com.github.mvysny.kaributesting.v10.mock.MockService
 import com.github.mvysny.kaributesting.v10.mock.MockVaadinServlet
 import com.github.mvysny.kaributesting.v10.mock.MockVaadinSession
 import com.github.mvysny.kaributesting.v10.mock.MockedUI
+import com.github.mvysny.kaributools.SemanticVersion
+import com.github.mvysny.kaributools.VaadinVersion
 import com.github.mvysny.kaributools.navigateTo
 import com.github.mvysny.kaributools.removeFromParent
 import com.vaadin.flow.component.AttachEvent
@@ -39,6 +41,10 @@ import kotlin.concurrent.thread
 import kotlin.concurrent.write
 import kotlin.test.expect
 
+fun SemanticVersion.isAtMost(major: Int): Boolean = this.major <= major
+@JvmOverloads
+fun SemanticVersion.isAtMost(major: Int, minor: Int, bugfix: Int = Int.MAX_VALUE): Boolean = this <= SemanticVersion(major, minor, bugfix)
+
 @DynaTestDsl
 internal fun DynaNodeGroup.mockVaadinTest() {
     lateinit var routes: Routes
@@ -65,7 +71,10 @@ internal fun DynaNodeGroup.mockVaadinTest() {
             expect(true) { VaadinSession.getCurrent().browser.locale != null }
             expect(false) { VaadinSession.getCurrent().browser.isIPhone }
             expect(true) { VaadinSession.getCurrent().browser.isFirefox }
-            expect(false) { VaadinSession.getCurrent().browser.isTooOldToFunctionProperly }
+            if (VaadinVersion.get.isAtMost(23, 3)) {
+                // Vaadin 23.4+ lacks Browser.isTooOldToFunctionProperly
+                expect(false) { VaadinSession.getCurrent().browser.isTooOldToFunctionProperly }
+            }
             expect(false) { VaadinSession.getCurrent().browser.isChrome }
             expect(false) { VaadinSession.getCurrent().browser.isChromeOS }
             expect(false) { VaadinSession.getCurrent().browser.isAndroid }