diff --git a/platform/util/src/com/intellij/util/lang/UrlClassLoader.java b/platform/util/src/com/intellij/util/lang/UrlClassLoader.java
index 4afc12c457f3..f4317b6d037c 100644
--- a/platform/util/src/com/intellij/util/lang/UrlClassLoader.java
+++ b/platform/util/src/com/intellij/util/lang/UrlClassLoader.java
@@ -18,6 +18,7 @@ package com.intellij.util.lang;
 import com.intellij.openapi.application.PathManager;
 import com.intellij.openapi.diagnostic.Logger;
 import com.intellij.openapi.util.SystemInfo;
+import com.intellij.openapi.util.io.FileUtil;
 import com.intellij.openapi.util.io.win32.IdeaWin32;
 import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.util.Function;
@@ -281,8 +282,7 @@ public class UrlClassLoader extends ClassLoader {
 
   @Nullable
   private Resource _getResource(final String name) {
-    String n = name;
-    n = StringUtil.trimStart(n, "/");
+    String n = StringUtil.trimStart(FileUtil.toCanonicalUriPath(name), "/");
     return getClassPath().getResource(n, true);
   }
 
diff --git a/platform/util/testSrc/com/intellij/util/lang/UrlClassLoaderTest.java b/platform/util/testSrc/com/intellij/util/lang/UrlClassLoaderTest.java
index f3c0ea5a3f08..b9d3b47b4a7d 100644
--- a/platform/util/testSrc/com/intellij/util/lang/UrlClassLoaderTest.java
+++ b/platform/util/testSrc/com/intellij/util/lang/UrlClassLoaderTest.java
@@ -52,6 +52,17 @@ public class UrlClassLoaderTest {
     assertNotNull(UrlClassLoader.build().allowBootstrapResources().get().getResourceAsStream(name));
   }
 
+  @Test
+  public void testNonCanonicalPaths() throws IOException {
+    File root = FileUtil.createTempDirectory("testNonCanonicalPaths", "");
+    File subDir = createTestDir(root, "dir");
+    createTestFile(subDir, "a.txt");
+
+    UrlClassLoader loader = UrlClassLoader.build().urls(root.toURI().toURL()).get();
+    assertNotNull(loader.getResourceAsStream("/dir/a.txt"));
+    assertNotNull(loader.getResourceAsStream("/dir/a.txt/../a.txt"));
+  }
+
   @Test
   public void testConcurrentResourceLoading() throws Exception {
     List<String> resourceNames = ContainerUtil.newArrayList();