diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/dircache/DirCacheCheckout.java b/org.eclipse.jgit/src/org/eclipse/jgit/dircache/DirCacheCheckout.java
index 22a855832..4c2988634 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/dircache/DirCacheCheckout.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/dircache/DirCacheCheckout.java
@@ -1015,10 +1015,9 @@ public class DirCacheCheckout {
 	}
 
 	private static boolean isValidPathSegment(CanonicalTreeParser t) {
-		boolean isWindows = "Windows".equals(SystemReader.getInstance()
-				.getProperty("os.name"));
-		boolean isOSX = "Mac OS X".equals(SystemReader.getInstance()
-				.getProperty("os.name"));
+		String osName = SystemReader.getInstance().getProperty("os.name");
+		boolean isWindows = "Windows".equals(osName);
+		boolean isOSX = "Darwin".equals(osName) || "Mac OS X".equals(osName);
 		boolean ignCase = isOSX || isWindows;
 
 		int ptr = t.getNameOffset();
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/util/FS_POSIX.java b/org.eclipse.jgit/src/org/eclipse/jgit/util/FS_POSIX.java
index c181a7a74..f04bb6fe0 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/util/FS_POSIX.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/util/FS_POSIX.java
@@ -105,6 +105,6 @@ abstract class FS_POSIX extends FS {
 						return System.getProperty("os.name");
 					}
 				});
-		return "Mac OS X".equals(osDotName);
+		return "Mac OS X".equals(osDotName) || "Darwin".equals(osDotName);
 	}
 }