diff --git a/src/celestia/celestiacore.cpp b/src/celestia/celestiacore.cpp
index eda8b0155..8397fda29 100644
--- a/src/celestia/celestiacore.cpp
+++ b/src/celestia/celestiacore.cpp
@@ -4765,7 +4765,7 @@ bool CelestiaCore::saveScreenShot(const fs::path& filename, ContentType type) co
     return false;
 }
 
-void CelestiaCore::setLogFile(fs::path &fn)
+void CelestiaCore::setLogFile(const fs::path &fn)
 {
     m_logfile = std::ofstream(fn.string());
     if (m_logfile.good())
diff --git a/src/celestia/celestiacore.h b/src/celestia/celestiacore.h
index 79c7f7d1b..0e78931b0 100644
--- a/src/celestia/celestiacore.h
+++ b/src/celestia/celestiacore.h
@@ -322,7 +322,7 @@ class CelestiaCore // : public Watchable<CelestiaCore>
 
     void notifyWatchers(int);
 
-    void setLogFile(fs::path&);
+    void setLogFile(const fs::path&);
 
     class Alerter
     {
diff --git a/src/celestia/qt/qtappwin.cpp b/src/celestia/qt/qtappwin.cpp
index 97a5dbc6b..27837bfa7 100644
--- a/src/celestia/qt/qtappwin.cpp
+++ b/src/celestia/qt/qtappwin.cpp
@@ -191,6 +191,10 @@ void CelestiaAppWindow::init(const QString& qConfigFileName,
                              const QStringList& qExtrasDirectories,
                              const QString& logFilename)
 {
+    QDir logPath = QDir(logFilename);
+    if (!logPath.makeAbsolute())
+        QMessageBox::warning(0, "Celestia", _("Error getting path for log filename!"));
+
     QString celestia_data_dir = QString::fromLocal8Bit(::getenv("CELESTIA_DATA_DIR"));
 
     if (celestia_data_dir.isEmpty()) {
@@ -233,7 +237,7 @@ void CelestiaAppWindow::init(const QString& qConfigFileName,
 
     if (!logFilename.isEmpty())
     {
-        fs::path fn(logFilename.toStdString());
+        fs::path fn = logPath.absolutePath().toStdString();
         m_appCore->setLogFile(fn);
     }