diff --git a/src/calamares/main.cpp b/src/calamares/main.cpp
index 989b5a928..d80c43d5d 100644
--- a/src/calamares/main.cpp
+++ b/src/calamares/main.cpp
@@ -20,10 +20,12 @@
 #include "CalamaresApplication.h"
 
 #include "kdsingleapplicationguard/kdsingleapplicationguard.h"
+#include "utils/CalamaresUtils.h"
 #include "utils/Logger.h"
 
 #include <QCommandLineParser>
 #include <QDebug>
+#include <QDir>
 
 int
 main( int argc, char *argv[] )
@@ -38,10 +40,17 @@ main( int argc, char *argv[] )
                                       "Verbose output for debugging purposes." );
     parser.addOption( debugOption );
 
+    QCommandLineOption configOption( QStringList() << "c" << "config",
+                                     "Configuration dir to use, for testing purposes.", "config" );
+    parser.addOption( configOption );
+
     parser.process( a );
 
     a.setDebug( parser.isSet( debugOption ) );
 
+    if ( parser.isSet( configOption ) )
+        CalamaresUtils::setAppDataDir( QDir( parser.value( configOption ) ) );
+
     KDSingleApplicationGuard guard( KDSingleApplicationGuard::AutoKillOtherInstances );
 
     int returnCode = 0;
diff --git a/src/libcalamares/utils/CalamaresUtils.cpp b/src/libcalamares/utils/CalamaresUtils.cpp
index cdf903c75..cfb374273 100644
--- a/src/libcalamares/utils/CalamaresUtils.cpp
+++ b/src/libcalamares/utils/CalamaresUtils.cpp
@@ -34,14 +34,26 @@
 namespace CalamaresUtils
 {
 
+static QDir s_appDataDir;
+
+void
+setAppDataDir( const QDir& dir )
+{
+    s_appDataDir = dir;
+}
+
+
 QDir
 appDataDir()
 {
-    QDir path( CMAKE_INSTALL_FULL_DATADIR );
-    if ( !path.exists() || !path.isReadable() )
-        path.mkpath( path.absolutePath() );
+    if ( s_appDataDir.path().isEmpty() )
+    {
+        s_appDataDir = QDir( CMAKE_INSTALL_FULL_DATADIR );
+        if ( !s_appDataDir.exists() || !s_appDataDir.isReadable() )
+            s_appDataDir.mkpath( s_appDataDir.absolutePath() );
+    }
 
-    return path;
+    return s_appDataDir;
 }
 
 
diff --git a/src/libcalamares/utils/CalamaresUtils.h b/src/libcalamares/utils/CalamaresUtils.h
index fdb0d053c..f7713be18 100644
--- a/src/libcalamares/utils/CalamaresUtils.h
+++ b/src/libcalamares/utils/CalamaresUtils.h
@@ -36,6 +36,10 @@ namespace CalamaresUtils
     DLLEXPORT QDir systemLibDir();
     DLLEXPORT void installTranslator( QObject* parent );
 
+    /**
+     * Override app data dir. Only for testing purposes.
+     */
+    DLLEXPORT void setAppDataDir( const QDir& dir );
 }
 
 #endif // CALAMARESUTILS_H