diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/util/FS_Win32_Cygwin.java b/org.eclipse.jgit/src/org/eclipse/jgit/util/FS_Win32_Cygwin.java
index 10be26f..41c239f 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/util/FS_Win32_Cygwin.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/util/FS_Win32_Cygwin.java
@@ -150,7 +150,7 @@
 		argv.add("sh.exe"); //$NON-NLS-1$
 		argv.add("-c"); //$NON-NLS-1$
 		argv.add("$0 \"$@\""); //$NON-NLS-1$
-		argv.add(cmd);
+		argv.add(cmd.replace(File.separatorChar, '/'));
 		argv.addAll(Arrays.asList(args));
 		ProcessBuilder proc = new ProcessBuilder();
 		proc.command(argv);