diff --git a/src/plugins/projectexplorer/project.cpp b/src/plugins/projectexplorer/project.cpp
index bdea6c9ef2b53e1fc166c69a28d2728db0e9f1db..12c47ee454bcf6fd0e197efe9df62cef204a1808 100644
--- a/src/plugins/projectexplorer/project.cpp
+++ b/src/plugins/projectexplorer/project.cpp
@@ -234,6 +234,8 @@ QString Project::projectDirectory() const
 
 QString Project::projectDirectory(const QString &proFile)
 {
+    if (proFile.isEmpty())
+        return QString();
     QFileInfo info(proFile);
     return info.absoluteDir().path();
 }
diff --git a/src/plugins/qt4projectmanager/qt4project.cpp b/src/plugins/qt4projectmanager/qt4project.cpp
index c56abe40fb5ccd79c8394803820883b9bd30868b..3e42ca965e81921c75a74f809e2d2ba1bbcf676f 100644
--- a/src/plugins/qt4projectmanager/qt4project.cpp
+++ b/src/plugins/qt4projectmanager/qt4project.cpp
@@ -793,6 +793,8 @@ QString Qt4Project::defaultTopLevelBuildDirectory() const
 
 QString Qt4Project::defaultTopLevelBuildDirectory(const QString &profilePath)
 {
+    if (profilePath.isEmpty())
+        return QString();
     QFileInfo info(profilePath);
     return QDir(projectDirectory(profilePath) + QLatin1String("/../") + info.baseName() + QLatin1String("-build")).absolutePath();
 }