diff --git a/java-compiler-testing/src/test/java/io/github/ascopes/jct/testing/unit/compilers/CompilableTest.java b/java-compiler-testing/src/test/java/io/github/ascopes/jct/testing/unit/compilers/CompilableTest.java
index 3bb5b8590..92b5888b3 100644
--- a/java-compiler-testing/src/test/java/io/github/ascopes/jct/testing/unit/compilers/CompilableTest.java
+++ b/java-compiler-testing/src/test/java/io/github/ascopes/jct/testing/unit/compilers/CompilableTest.java
@@ -47,6 +47,7 @@
 import org.junit.jupiter.params.provider.ValueSource;
 import org.mockito.Mock;
 import org.mockito.junit.jupiter.MockitoExtension;
+import org.mockito.quality.Strictness;
 
 /**
  * {@link Compilable} tests.
@@ -290,7 +291,10 @@ static Stream<DynamicTest> addPackagePathTestsFor(
         () -> {
           // Given
           var pathLike = stub(PathLike.class);
-          Compilable<?, ?> compiler = mockCast(new TypeRef<>() {}, withSettings().lenient());
+          Compilable<?, ?> compiler = mockCast(
+              new TypeRef<>() {},
+              withSettings().strictness(Strictness.LENIENT)
+          );
           given(compiler.addPath(any(), any(PathLike.class))).will(ctx -> compiler);
           // Stub this method to keep results consistent, even though we shouldn't call it.
           // Just keeps the failure test results consistent and meaningful.
@@ -310,7 +314,10 @@ static Stream<DynamicTest> addPackagePathTestsFor(
         () -> {
           // Given
           var path = stub(Path.class);
-          Compilable<?, ?> compiler = mockCast(new TypeRef<>() {}, withSettings().lenient());
+          Compilable<?, ?> compiler = mockCast(
+              new TypeRef<>() {},
+              withSettings().strictness(Strictness.LENIENT)
+          );
           given(compiler.addPath(any(), any(Path.class))).will(ctx -> compiler);
           // Stub this method to keep results consistent, even though we shouldn't call it.
           // Just keeps the failure test results consistent and meaningful.
@@ -330,7 +337,10 @@ static Stream<DynamicTest> addPackagePathTestsFor(
         () -> {
           // Given
           var pathLike = stub(PathLike.class);
-          Compilable<?, ?> compiler = mockCast(new TypeRef<>() {}, withSettings().lenient());
+          Compilable<?, ?> compiler = mockCast(
+              new TypeRef<>() {},
+              withSettings().strictness(Strictness.LENIENT)
+          );
           given(compiler.addPath(any(), any(PathLike.class))).will(ctx -> compiler);
           given(pathLikeAdder.add(compiler, pathLike)).willCallRealMethod();
 
@@ -347,7 +357,10 @@ static Stream<DynamicTest> addPackagePathTestsFor(
         () -> {
           // Given
           var path = stub(Path.class);
-          Compilable<?, ?> compiler = mockCast(new TypeRef<>() {}, withSettings().lenient());
+          Compilable<?, ?> compiler = mockCast(
+              new TypeRef<>() {},
+              withSettings().strictness(Strictness.LENIENT)
+          );
           given(compiler.addPath(any(), any(Path.class))).will(ctx -> compiler);
           given(pathAdder.add(compiler, path)).willCallRealMethod();
 
@@ -403,7 +416,10 @@ static Stream<DynamicTest> addModulePathTestsFor(
         () -> {
           // Given
           var pathLike = stub(PathLike.class);
-          Compilable<?, ?> compiler = mockCast(new TypeRef<>() {}, withSettings().lenient());
+          Compilable<?, ?> compiler = mockCast(
+              new TypeRef<>() {},
+              withSettings().strictness(Strictness.LENIENT)
+          );
           // Stub this method to keep results consistent, even though we shouldn't call it.
           // Just keeps the failure test results consistent and meaningful.
           given(compiler.addPath(any(), any(PathLike.class))).will(ctx -> compiler);
@@ -423,7 +439,10 @@ static Stream<DynamicTest> addModulePathTestsFor(
         () -> {
           // Given
           var path = stub(Path.class);
-          Compilable<?, ?> compiler = mockCast(new TypeRef<>() {}, withSettings().lenient());
+          Compilable<?, ?> compiler = mockCast(
+              new TypeRef<>() {},
+              withSettings().strictness(Strictness.LENIENT)
+          );
           // Stub this method to keep results consistent, even though we shouldn't call it.
           // Just keeps the failure test results consistent and meaningful.
           given(compiler.addPath(any(), any(Path.class))).will(ctx -> compiler);
@@ -443,7 +462,10 @@ static Stream<DynamicTest> addModulePathTestsFor(
         () -> {
           // Given
           var pathLike = stub(PathLike.class);
-          Compilable<?, ?> compiler = mockCast(new TypeRef<>() {}, withSettings().lenient());
+          Compilable<?, ?> compiler = mockCast(
+              new TypeRef<>() {},
+              withSettings().strictness(Strictness.LENIENT)
+          );
           given(compiler.addPath(any(), any(PathLike.class))).will(ctx -> compiler);
           given(pathLikeAdder.add(compiler, moduleName, pathLike)).willCallRealMethod();
 
@@ -460,7 +482,10 @@ static Stream<DynamicTest> addModulePathTestsFor(
         () -> {
           // Given
           var path = stub(Path.class);
-          Compilable<?, ?> compiler = mockCast(new TypeRef<>() {}, withSettings().lenient());
+          Compilable<?, ?> compiler = mockCast(
+              new TypeRef<>() {},
+              withSettings().strictness(Strictness.LENIENT)
+          );
           given(compiler.addPath(any(), any(Path.class))).will(ctx -> compiler);
           given(pathAdder.add(compiler, moduleName, path)).willCallRealMethod();
 
diff --git a/java-compiler-testing/src/test/java/io/github/ascopes/jct/testing/unit/compilers/SimpleCompilationFactoryTest.java b/java-compiler-testing/src/test/java/io/github/ascopes/jct/testing/unit/compilers/SimpleCompilationFactoryTest.java
index d1c3b317c..6ca843f8d 100644
--- a/java-compiler-testing/src/test/java/io/github/ascopes/jct/testing/unit/compilers/SimpleCompilationFactoryTest.java
+++ b/java-compiler-testing/src/test/java/io/github/ascopes/jct/testing/unit/compilers/SimpleCompilationFactoryTest.java
@@ -50,6 +50,7 @@
 import org.mockito.Answers;
 import org.mockito.Mock;
 import org.mockito.junit.jupiter.MockitoExtension;
+import org.mockito.quality.Strictness;
 
 /**
  * {@link SimpleCompilationFactory} tests.
@@ -64,19 +65,19 @@ class SimpleCompilationFactoryTest {
 
   SimpleCompilationFactory<StubbedCompiler> compilationFactory;
 
-  @Mock(lenient = true, answer = Answers.RETURNS_DEEP_STUBS)
+  @Mock(strictness = Strictness.LENIENT, answer = Answers.RETURNS_DEEP_STUBS)
   StubbedCompiler compiler;
 
-  @Mock(lenient = true, answer = Answers.RETURNS_SMART_NULLS)
+  @Mock(strictness = Strictness.LENIENT, answer = Answers.RETURNS_SMART_NULLS)
   JavaCompiler jsr199Compiler;
 
-  @Mock(lenient = true, answer = Answers.RETURNS_SELF)
+  @Mock(strictness = Strictness.LENIENT, answer = Answers.RETURNS_SELF)
   FlagBuilder flagBuilder;
 
-  @Mock(lenient = true, answer = Answers.RETURNS_SMART_NULLS)
+  @Mock(strictness = Strictness.LENIENT, answer = Answers.RETURNS_SMART_NULLS)
   CompilationTask compilationTask;
 
-  @Mock(lenient = true, answer = Answers.RETURNS_DEEP_STUBS)
+  @Mock(strictness = Strictness.LENIENT, answer = Answers.RETURNS_DEEP_STUBS)
   SimpleFileManagerTemplate fileManagerTemplate;
 
   Boolean expectedCompilationResult;
diff --git a/java-compiler-testing/src/test/java/io/github/ascopes/jct/testing/unit/jsr199/diagnostics/TracingDiagnosticListenerTest.java b/java-compiler-testing/src/test/java/io/github/ascopes/jct/testing/unit/jsr199/diagnostics/TracingDiagnosticListenerTest.java
index eb63b11dd..14de8bf3b 100644
--- a/java-compiler-testing/src/test/java/io/github/ascopes/jct/testing/unit/jsr199/diagnostics/TracingDiagnosticListenerTest.java
+++ b/java-compiler-testing/src/test/java/io/github/ascopes/jct/testing/unit/jsr199/diagnostics/TracingDiagnosticListenerTest.java
@@ -53,6 +53,7 @@
 import org.junit.jupiter.params.provider.Arguments;
 import org.junit.jupiter.params.provider.EnumSource;
 import org.junit.jupiter.params.provider.MethodSource;
+import org.mockito.quality.Strictness;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -388,7 +389,7 @@ static Stream<Arguments> loggingDisabledArgs() {
   static Diagnostic<JavaFileObject> someDiagnostic(Kind kind, String message) {
     var diagnostic = stubCast(
         new TypeRef<Diagnostic<JavaFileObject>>() {},
-        withSettings().lenient()
+        withSettings().strictness(Strictness.LENIENT)
     );
     when(diagnostic.getKind()).thenReturn(kind);
     when(diagnostic.getMessage(any())).thenReturn(message);
diff --git a/pom.xml b/pom.xml
index 2cabbf7b0..dad1c77aa 100644
--- a/pom.xml
+++ b/pom.xml
@@ -129,7 +129,7 @@
         <!-- Mocking -->
         <groupId>org.mockito</groupId>
         <artifactId>mockito-bom</artifactId>
-        <version>4.5.1</version>
+        <version>4.6.0</version>
         <scope>import</scope>
         <type>pom</type>
       </dependency>