diff --git a/doc/operations.qdoc b/doc/operations.qdoc
index 762d1233..56518065 100644
--- a/doc/operations.qdoc
+++ b/doc/operations.qdoc
@@ -188,6 +188,8 @@
                 persistently. This is currently only supported on Windows.
                 If \c system is set to \c true, the persistent variable is set
                 system-wide, not only for the current user.
+                Note, if you set path to environment variable, use '\\' as separator, for example:
+                @Targetdir@\\lib\\system.
         \row
             \li RegisterFileType
             \li "RegisterFileType" \c extension \c command [\c description [\c contentType [\c icon]]].
diff --git a/src/libs/installer/environmentvariablesoperation.cpp b/src/libs/installer/environmentvariablesoperation.cpp
index 006ea376..1f3b56d5 100644
--- a/src/libs/installer/environmentvariablesoperation.cpp
+++ b/src/libs/installer/environmentvariablesoperation.cpp
@@ -152,8 +152,18 @@ UpdateOperation::Error undoSetting(const QString &regPath,
         SettingsType registry(regPath, QSettingsWrapper::NativeFormat);
         actual = registry.value(name).toString();
     }
-    if (actual != value) //key changed, don't undo
-        return UpdateOperation::UserDefinedError;
+
+    if (actual != value)
+    {
+        //For unknown reason paths with @TargetDir@ variable get modified
+        //so that Windows file separators get replaced with unix style separators,
+        //fix separators before matching to actual value in register
+        QString tempValue = value;
+        QString fixedValue = tempValue.replace(QLatin1Char('/'), QLatin1Char('\\'));
+
+        if (actual != fixedValue) //key changed, don't undo
+            return UpdateOperation::UserDefinedError;
+    }
 
     bool error = false;
     if (handleRegExpandSz(regPath, name, oldValue, errorString, &error))