diff --git a/documentation/documentation.gradle.kts b/documentation/documentation.gradle.kts
index b0327e7de14b..deb257c580bf 100644
--- a/documentation/documentation.gradle.kts
+++ b/documentation/documentation.gradle.kts
@@ -140,8 +140,7 @@ val jdkJavadocBaseUrl = "https://docs.oracle.com/en/java/javase/${JavaVersion.cu
 val elementListsDir = layout.buildDirectory.dir("elementLists")
 val externalModulesWithoutModularJavadoc = mapOf(
 		"org.apiguardian.api" to "https://apiguardian-team.github.io/apiguardian/docs/$apiGuardianDocVersion/api/",
-		"org.assertj.core" to "https://javadoc.io/doc/org.assertj/assertj-core/${libs.versions.assertj.get()}/",
-		"org.opentest4j" to "https://ota4j-team.github.io/opentest4j/docs/$ota4jDocVersion/api/"
+		"org.opentest4j" to "https://ota4j-team.github.io/opentest4j/docs/1.3.0/api/",
 )
 require(externalModulesWithoutModularJavadoc.values.all { it.endsWith("/") }) {
 	"all base URLs must end with a trailing slash: $externalModulesWithoutModularJavadoc"
@@ -419,6 +418,10 @@ tasks {
 
 			links(jdkJavadocBaseUrl)
 			links("https://junit.org/junit4/javadoc/${libs.versions.junit4.get()}/")
+			val assertJVersion = libs.versions.assertj.get()
+			if (!assertJVersion.endsWith("-SNAPSHOT")) {
+				links("https://javadoc.io/doc/org.assertj/assertj-core/$assertJVersion/")
+			}
 			externalModulesWithoutModularJavadoc.forEach { (moduleName, baseUrl) ->
 				linksOffline(baseUrl, elementListsDir.get().asFile.resolve(moduleName).absolutePath)
 			}
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index 54536f54b6d4..0ea272503eb6 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -3,7 +3,7 @@ ant = "1.10.15"
 apiguardian = "1.1.2"
 asciidoctorj-pdf = "2.3.19"
 asciidoctor-plugins = "4.0.4" # Check if workaround in documentation.gradle.kts can be removed when upgrading
-assertj = "3.27.3"
+assertj = "4.0.0-SNAPSHOT"
 bnd = "7.1.0"
 checkstyle = "11.0.0"
 eclipse = "4.36.0"
diff --git a/jupiter-tests/src/test/java/org/junit/jupiter/engine/execution/ParameterResolutionUtilsTests.java b/jupiter-tests/src/test/java/org/junit/jupiter/engine/execution/ParameterResolutionUtilsTests.java
index de3301e61ef9..9a9c3a1a70f9 100644
--- a/jupiter-tests/src/test/java/org/junit/jupiter/engine/execution/ParameterResolutionUtilsTests.java
+++ b/jupiter-tests/src/test/java/org/junit/jupiter/engine/execution/ParameterResolutionUtilsTests.java
@@ -258,7 +258,7 @@ void reportTypeMismatchBetweenParameterAndResolvedParameterWithArrayTypes() {
 
 		assertThatExceptionOfType(ParameterResolutionException.class)//
 				.isThrownBy(this::resolveMethodParameters)//
-				.withMessageContaining(//
+				.withMessageContainingAll(//
 					"resolved a value of type [int[][]] for parameter [java.lang.String[]", //
 					"in method", //
 					"but a value assignment compatible with [java.lang.String[]] is required." //
diff --git a/platform-tests/src/test/java/org/junit/platform/launcher/core/DefaultLauncherTests.java b/platform-tests/src/test/java/org/junit/platform/launcher/core/DefaultLauncherTests.java
index bc3ede9085d5..aea5e206ab2f 100644
--- a/platform-tests/src/test/java/org/junit/platform/launcher/core/DefaultLauncherTests.java
+++ b/platform-tests/src/test/java/org/junit/platform/launcher/core/DefaultLauncherTests.java
@@ -854,7 +854,7 @@ void reportsEngineExecutionFailureOnUnresolvedUniqueIdSelectorWithEnginePrefix()
 				.isInstanceOf(DiscoveryIssueException.class) //
 				.hasMessageStartingWith(
 					"TestEngine with ID 'some-engine' encountered a critical issue during test discovery") //
-				.hasMessageContaining("(1) [ERROR] %s could not be resolved", selector);
+				.hasMessageContaining("(1) [ERROR] %s could not be resolved".formatted(selector));
 	}
 
 	@Test
@@ -877,7 +877,7 @@ void reportsEngineExecutionFailureForSelectorResolutionFailure() {
 				.isInstanceOf(DiscoveryIssueException.class) //
 				.hasMessageStartingWith(
 					"TestEngine with ID 'some-engine' encountered a critical issue during test discovery") //
-				.hasMessageContaining("(1) [ERROR] %s resolution failed", selector) //
+				.hasMessageContaining("(1) [ERROR] %s resolution failed".formatted(selector)) //
 				.hasMessageContaining("Cause: java.lang.RuntimeException: boom");
 	}
 
diff --git a/settings.gradle.kts b/settings.gradle.kts
index 53dc8d7c4f78..8223498df440 100644
--- a/settings.gradle.kts
+++ b/settings.gradle.kts
@@ -16,6 +16,11 @@ plugins {
 dependencyResolutionManagement {
 	repositories {
 		mavenCentral()
+		maven(url = "https://central.sonatype.com/repository/maven-snapshots/") {
+			mavenContent {
+				snapshotsOnly()
+			}
+		}
 	}
 	repositoriesMode = FAIL_ON_PROJECT_REPOS
 }