diff --git a/include/log.h b/include/log.h
index c908eee9..87e0ae01 100644
--- a/include/log.h
+++ b/include/log.h
@@ -20,5 +20,6 @@ void logError(QString message);
 void log(QString message, LogType type);
 QString getLogPath();
 QString getMostRecentError();
+bool cleanupLargeLog();
 
 #endif // LOG_H
diff --git a/src/log.cpp b/src/log.cpp
index 3b5d5eb0..64f6753a 100644
--- a/src/log.cpp
+++ b/src/log.cpp
@@ -86,3 +86,14 @@ QString getLogPath() {
 QString getMostRecentError() {
     return mostRecentError;
 }
+
+bool cleanupLargeLog() {
+    QFile logFile(getLogPath());
+    if (logFile.size() < 20000000)
+        return false;
+
+    bool removed = logFile.remove();
+    if (removed)
+        logWarn(QString("Previous log file %1 was cleared due to being over 20MB in size.").arg(getLogPath()));
+    return removed;
+}
diff --git a/src/mainwindow.cpp b/src/mainwindow.cpp
index d98ed68a..e2ae8bdb 100644
--- a/src/mainwindow.cpp
+++ b/src/mainwindow.cpp
@@ -53,6 +53,8 @@ MainWindow::MainWindow(QWidget *parent) :
     QApplication::setWindowIcon(QIcon(":/icons/porymap-icon-2.ico"));
     ui->setupUi(this);
 
+    cleanupLargeLog();
+
     this->initWindow();
     if (!this->openRecentProject()) {
         // Re-initialize everything to a blank slate if opening the recent project failed.