diff --git a/spring-core/src/main/java/org/springframework/aot/nativex/FileNativeConfigurationWriter.java b/spring-core/src/main/java/org/springframework/aot/nativex/FileNativeConfigurationWriter.java
index 4822734106b0..3a0e364701e0 100644
--- a/spring-core/src/main/java/org/springframework/aot/nativex/FileNativeConfigurationWriter.java
+++ b/spring-core/src/main/java/org/springframework/aot/nativex/FileNativeConfigurationWriter.java
@@ -20,6 +20,7 @@
 import java.io.FileWriter;
 import java.io.IOException;
 import java.io.Writer;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Path;
 import java.util.function.Consumer;
 
@@ -59,7 +60,7 @@ public FileNativeConfigurationWriter(Path basePath, @Nullable String groupId, @N
 	protected void writeTo(String fileName, Consumer<BasicJsonWriter> writer) {
 		try {
 			File file = createIfNecessary(fileName);
-			try (FileWriter out = new FileWriter(file)) {
+			try (FileWriter out = new FileWriter(file, StandardCharsets.UTF_8)) {
 				writer.accept(createJsonWriter(out));
 			}
 		}
diff --git a/spring-core/src/test/java/org/springframework/aot/nativex/FileNativeConfigurationWriterTests.java b/spring-core/src/test/java/org/springframework/aot/nativex/FileNativeConfigurationWriterTests.java
index 8406cba53305..3a0ad7cecd7c 100644
--- a/spring-core/src/test/java/org/springframework/aot/nativex/FileNativeConfigurationWriterTests.java
+++ b/spring-core/src/test/java/org/springframework/aot/nativex/FileNativeConfigurationWriterTests.java
@@ -18,6 +18,7 @@
 
 import java.io.IOException;
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.function.Consumer;
@@ -176,6 +177,17 @@ void resourceConfig() throws IOException, JSONException {
 				}""");
 	}
 
+	@Test
+	void resourceConfigWithNonAsciiPatternIsWrittenAsUtf8() throws IOException {
+		FileNativeConfigurationWriter generator = new FileNativeConfigurationWriter(tempDir);
+		RuntimeHints hints = new RuntimeHints();
+		hints.resources().registerPattern("com/example/café/**");
+		generator.write(hints);
+		Path jsonFile = tempDir.resolve("META-INF").resolve("native-image").resolve("reachability-metadata.json");
+		byte[] content = Files.readAllBytes(jsonFile);
+		assertThat(content).containsSequence("café".getBytes(StandardCharsets.UTF_8));
+	}
+
 	@Test
 	void namespace() {
 		String groupId = "foo.bar";