diff --git a/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/AutomaticModuleNamingTest.java b/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/AutomaticModuleNamingTest.java
index 4f7bf13..4693025 100644
--- a/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/AutomaticModuleNamingTest.java
+++ b/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/AutomaticModuleNamingTest.java
@@ -114,4 +114,9 @@
 				new String(determineAutomaticModuleNameFromFileName("CLASSES12.ZIP", true, true)));
 	}
 
+	public void testBug529680() throws Exception {
+		assertEquals("hibernate.jpa", new String(
+				determineAutomaticModuleNameFromFileName("hibernate-jpa-2.1-api-1.0.0.Final.jar", true, true)));
+	}
+
 }
diff --git a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/env/AutomaticModuleNaming.java b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/env/AutomaticModuleNaming.java
index 765c0a1..bb1c9d1 100644
--- a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/env/AutomaticModuleNaming.java
+++ b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/env/AutomaticModuleNaming.java
@@ -95,7 +95,7 @@
 		dashLoop: for (index = start; index < end - 1; index++) {
 			if (name.charAt(index) == '-' && name.charAt(index + 1) >= '0' && name.charAt(index + 1) <= '9') {
 				for (int index2 = index + 2; index2 < end; index2++) {
-					final char c = name.charAt(index2 + 1);
+					final char c = name.charAt(index2);
 					if (c == '.') {
 						break;
 					}