diff --git a/src/libs/extensionsystem/pluginspec.cpp b/src/libs/extensionsystem/pluginspec.cpp
index 11f52f2eda603cc11ac423ac59f3191653135698..e60dece35002627e09baae4b9cdfdae0b826fce1 100644
--- a/src/libs/extensionsystem/pluginspec.cpp
+++ b/src/libs/extensionsystem/pluginspec.cpp
@@ -34,6 +34,7 @@
 #include "iplugin_p.h"
 #include "pluginmanager.h"
 
+#include <QtCore/QDir>
 #include <QtCore/QFile>
 #include <QtCore/QFileInfo>
 #include <QtCore/QXmlStreamReader>
@@ -787,7 +788,8 @@ bool PluginSpecPrivate::loadLibrary()
     PluginLoader loader(libName);
     if (!loader.load()) {
         hasError = true;
-        errorString = libName + QString::fromLatin1(": ") + loader.errorString();
+        errorString = QDir::toNativeSeparators(libName)
+            + QString::fromLatin1(": ") + loader.errorString();
         return false;
     }
     IPlugin *pluginObject = qobject_cast<IPlugin*>(loader.instance());