diff --git a/core/pom.xml b/core/pom.xml
index caaf149fb..cf0fc9a0f 100644
--- a/core/pom.xml
+++ b/core/pom.xml
@@ -154,6 +154,12 @@
       <artifactId>truth</artifactId>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>com.google.jimfs</groupId>
+      <artifactId>jimfs</artifactId>
+      <version>1.3.2</version>
+      <scope>test</scope>
+    </dependency>
     <dependency>
       <groupId>org.mockito</groupId>
       <artifactId>mockito-core</artifactId>
diff --git a/core/src/main/java/com/google/adk/skills/LocalSkillSource.java b/core/src/main/java/com/google/adk/skills/LocalSkillSource.java
index 8cb465521..8ed2a91be 100644
--- a/core/src/main/java/com/google/adk/skills/LocalSkillSource.java
+++ b/core/src/main/java/com/google/adk/skills/LocalSkillSource.java
@@ -23,6 +23,7 @@
 import static com.google.common.collect.ImmutableList.toImmutableList;
 import static java.nio.file.Files.isDirectory;
 
+import com.google.common.base.Joiner;
 import com.google.common.collect.ImmutableList;
 import io.reactivex.rxjava3.core.Flowable;
 import io.reactivex.rxjava3.core.Maybe;
@@ -37,6 +38,8 @@
 /** Loads skills from the local file system. */
 public final class LocalSkillSource extends AbstractSkillSource<Path> {
 
+  private static final Joiner PATH_JOINER = Joiner.on('/');
+
   private final Path skillsBasePath;
 
   public LocalSkillSource(Path skillsBasePath) {
@@ -71,7 +74,9 @@ public Single<ImmutableList<String>> listResources(String skillName, String reso
                 return paths
                     .filter(Files::isRegularFile)
                     .map(skillDir::relativize)
-                    .map(Path::toString)
+                    // Join the path's name elements with '/' on every OS, not the platform
+                    // separator, to match ClassPathSkillSource and InMemorySkillSource.
+                    .map(relativePath -> PATH_JOINER.join(relativePath))
                     .collect(toImmutableList());
               }
             })
diff --git a/core/src/test/java/com/google/adk/skills/LocalSkillSourceTest.java b/core/src/test/java/com/google/adk/skills/LocalSkillSourceTest.java
index d66cfe283..5d6a629cd 100644
--- a/core/src/test/java/com/google/adk/skills/LocalSkillSourceTest.java
+++ b/core/src/test/java/com/google/adk/skills/LocalSkillSourceTest.java
@@ -23,7 +23,10 @@
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.io.ByteSource;
+import com.google.common.jimfs.Configuration;
+import com.google.common.jimfs.Jimfs;
 import java.io.IOException;
+import java.nio.file.FileSystem;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import org.junit.Rule;
@@ -96,6 +99,27 @@ public void testListResources() throws IOException {
     assertThat(resources).containsExactly("assets/file1.txt", "assets/subdir/file2.txt");
   }
 
+  @Test
+  public void testListResources_windowsFileSystem() throws IOException {
+    // Use Windows paths on any host so Ubuntu CI covers separator normalization.
+    try (FileSystem fileSystem = Jimfs.newFileSystem(Configuration.windows())) {
+      Path skillsBase = fileSystem.getPath("C:\\skills");
+      Path assetsDir = skillsBase.resolve("my-skill").resolve("assets");
+      Files.createDirectories(assetsDir.resolve("subdir"));
+      Files.writeString(assetsDir.resolve("file1.txt"), "resource content");
+      Files.writeString(assetsDir.resolve("subdir").resolve("file2.txt"), "resource content");
+
+      SkillSource source = new LocalSkillSource(skillsBase);
+      ImmutableList<String> resources = source.listResources("my-skill", "assets").blockingGet();
+
+      assertThat(resources).containsExactly("assets/file1.txt", "assets/subdir/file2.txt");
+      for (String resourcePath : resources) {
+        ByteSource resource = source.loadResource("my-skill", resourcePath).blockingGet();
+        assertThat(new String(resource.read(), UTF_8)).isEqualTo("resource content");
+      }
+    }
+  }
+
   @Test
   public void testListResources_notDirectory() throws IOException {
     Path skillsBase = tempFolder.getRoot().toPath().resolve("skills");