diff --git a/src/main/java/org/cryptomator/launcher/AdminPropertiesSetter.java b/src/main/java/org/cryptomator/launcher/AdminPropertiesSetter.java
index 36c7dd247..12d1c50da 100644
--- a/src/main/java/org/cryptomator/launcher/AdminPropertiesSetter.java
+++ b/src/main/java/org/cryptomator/launcher/AdminPropertiesSetter.java
@@ -92,7 +92,7 @@ class AdminPropertiesSetter {
 		return systemProps;
 	}
 
-	private static Map<String, Object> loadAdminProperties(Path adminPropertiesPath) {
+	static Map<String, Object> loadAdminProperties(Path adminPropertiesPath) {
 		try (var in = Files.newInputStream(adminPropertiesPath, StandardOpenOption.READ)) {
 			var map = JSON.readValue(in, new TypeReference<Map<String, Object>>() {});
 			if (map == null) {
diff --git a/src/main/java/org/cryptomator/launcher/BufferedLog.java b/src/main/java/org/cryptomator/launcher/BufferedLog.java
index 0facf7734..68eb75e26 100644
--- a/src/main/java/org/cryptomator/launcher/BufferedLog.java
+++ b/src/main/java/org/cryptomator/launcher/BufferedLog.java
@@ -15,7 +15,7 @@ class BufferedLog {
 	record Entry(String className, String message, List<Object> messageInput) {}
 
 	synchronized static void log(String className, String message, List<Object> messageInput) {
-		logMessages.add(new BufferedLog.Entry(className, message, messageInput));
+		logMessages.add(new Entry(className, message, messageInput));
 	}
 
 	synchronized static void flushTo(Logger log) {
diff --git a/src/test/java/org/cryptomator/launcher/AdminPropertiesSetterTest.java b/src/test/java/org/cryptomator/launcher/AdminPropertiesSetterTest.java
new file mode 100644
index 000000000..31b6be658
--- /dev/null
+++ b/src/test/java/org/cryptomator/launcher/AdminPropertiesSetterTest.java
@@ -0,0 +1,98 @@
+package org.cryptomator.launcher;
+
+import com.fasterxml.jackson.databind.json.JsonMapper;
+import org.hamcrest.MatcherAssert;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+import org.mockito.Answers;
+import org.mockito.Mockito;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardOpenOption;
+import java.util.List;
+import java.util.Map;
+
+import static org.hamcrest.Matchers.anEmptyMap;
+import static org.hamcrest.Matchers.hasEntry;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyString;
+
+public class AdminPropertiesSetterTest {
+
+	private static final Map<String, Object> NO_STRING_CONFIG = Map.of("list", List.of("a", "b", "c"), //
+			"map", Map.of("a", 1, "b", 2));
+
+	private static final Map<String, Object> CONFIG = Map.of("kack", "dudel", //
+			"list", List.of("a", "b", "c"), //
+			"map", Map.of("a", 1, "b", 2));
+
+	@Test
+	@DisplayName("Loading valid JSON")
+	void loadValidJson(@TempDir Path path) throws IOException {
+		try (var adminPropSetterMock = Mockito.mockStatic(AdminPropertiesSetter.class)) {
+			adminPropSetterMock.when(() -> AdminPropertiesSetter.log(anyString(), any())).thenAnswer(Answers.RETURNS_DEFAULTS);
+			adminPropSetterMock.when(() -> AdminPropertiesSetter.loadAdminProperties(any())).thenCallRealMethod();
+			var configPath = path.resolve("config.json");
+			setupValidJson(configPath);
+
+			var result = AdminPropertiesSetter.loadAdminProperties(configPath);
+			Assertions.assertAll(CONFIG.entrySet().stream().map((e) -> //
+					() -> MatcherAssert.assertThat(result, hasEntry(e.getKey(), e.getValue()))));
+		}
+	}
+
+	@Test
+	@DisplayName("Loading not existing file")
+	void loadNotExistingFile(@TempDir Path path) {
+		try (var adminPropSetterMock = Mockito.mockStatic(AdminPropertiesSetter.class)) {
+			adminPropSetterMock.when(() -> AdminPropertiesSetter.log(anyString(), any())).thenAnswer(Answers.RETURNS_DEFAULTS);
+			adminPropSetterMock.when(() -> AdminPropertiesSetter.loadAdminProperties(any())).thenCallRealMethod();
+			var configPath = path.resolve("config.json");
+
+			var result = AdminPropertiesSetter.loadAdminProperties(configPath);
+			MatcherAssert.assertThat(result, anEmptyMap());
+			adminPropSetterMock.verify(() -> AdminPropertiesSetter.log(anyString(), any()));
+		}
+	}
+
+	@Test
+	@DisplayName("Loading empty file")
+	void loadEmptyFile(@TempDir Path path) throws IOException {
+		try (var adminPropSetterMock = Mockito.mockStatic(AdminPropertiesSetter.class)) {
+			adminPropSetterMock.when(() -> AdminPropertiesSetter.log(anyString(), any())).thenAnswer(Answers.RETURNS_DEFAULTS);
+			adminPropSetterMock.when(() -> AdminPropertiesSetter.loadAdminProperties(any())).thenCallRealMethod();
+			var configPath = path.resolve("config.json");
+			Files.createFile(configPath);
+
+			var result = AdminPropertiesSetter.loadAdminProperties(configPath);
+			MatcherAssert.assertThat(result, anEmptyMap());
+			adminPropSetterMock.verify(() -> AdminPropertiesSetter.log(anyString(), any()));
+		}
+	}
+
+	void setupValidJson(Path p) throws IOException {
+		var json = JsonMapper.builder().build();
+		try (var out = Files.newOutputStream(p, StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING, StandardOpenOption.WRITE)) {
+			json.writerWithDefaultPrettyPrinter().writeValue(out, CONFIG);
+		}
+	}
+
+	@Test
+	@DisplayName("Keys with non-String values are ignored")
+	void ignoreValues(@TempDir Path path) {
+		try (var adminPropSetterMock = Mockito.mockStatic(AdminPropertiesSetter.class)) {
+			adminPropSetterMock.when(() -> AdminPropertiesSetter.log(anyString(), any())).thenAnswer(Answers.RETURNS_DEFAULTS);
+			adminPropSetterMock.when(() -> AdminPropertiesSetter.loadAdminProperties(any())).thenReturn(NO_STRING_CONFIG);
+			adminPropSetterMock.when(AdminPropertiesSetter::adjustSystemProperties).thenCallRealMethod();
+
+			AdminPropertiesSetter.adjustSystemProperties();
+			adminPropSetterMock.verify(() -> AdminPropertiesSetter.log(anyString(), any()), Mockito.times(NO_STRING_CONFIG.size()));
+		}
+	}
+
+
+}