diff --git a/include/mainwindow.h b/include/mainwindow.h
index 1bf1c54c..c575a6ec 100644
--- a/include/mainwindow.h
+++ b/include/mainwindow.h
@@ -277,7 +277,6 @@ private:
     QString getDefaultMap();
     void setRecentMap(QString map_name);
     QStandardItem* createMapItem(QString mapName, int groupNum, int inGroupNum);
-    bool mapDimensionsValid(int width, int height);
 
     void drawMapListIcons(QAbstractItemModel *model);
     void updateMapList();
diff --git a/include/project.h b/include/project.h
index 298e1351..c8f722d2 100644
--- a/include/project.h
+++ b/include/project.h
@@ -149,6 +149,7 @@ public:
     QStringList getVisibilities();
     QMap<QString, QStringList> getTilesetLabels();
     bool readTilesetProperties();
+    bool readMaxMapDataSize();
     bool readRegionMapSections();
     bool readItemNames();
     bool readFlagNames();
@@ -188,8 +189,8 @@ public:
     static int getDefaultMapSize();
     static int getMaxMapWidth();
     static int getMaxMapHeight();
-
-    int getMapDataSize(int width, int height);
+    static int getMapDataSize(int width, int height);
+    static bool mapDimensionsValid(int width, int height);
     bool calculateDefaultMapSize();
 
 private:
diff --git a/src/mainwindow.cpp b/src/mainwindow.cpp
index d33b8309..e0104933 100644
--- a/src/mainwindow.cpp
+++ b/src/mainwindow.cpp
@@ -701,6 +701,7 @@ bool MainWindow::loadDataStructures() {
                 && project->readTrainerTypes()
                 && project->readMetatileBehaviors()
                 && project->readTilesetProperties()
+                && project->readMaxMapDataSize()
                 && project->readHealLocations()
                 && project->readMiscellaneousConstants()
                 && project->readSpeciesIconPaths()
@@ -2351,10 +2352,6 @@ void MainWindow::on_pushButton_ChangeDimensions_clicked()
     }
 }
 
-bool MainWindow::mapDimensionsValid(int width, int height) {
-    return editor->project->getMapDataSize(width, height) <= editor->project->getMaxMapDataSize();
-}
-
 void MainWindow::on_checkBox_smartPaths_stateChanged(int selected)
 {
     bool enabled = selected == Qt::Checked;
diff --git a/src/mainwindow_scriptapi.cpp b/src/mainwindow_scriptapi.cpp
index 7f6cc24c..1df8afb9 100644
--- a/src/mainwindow_scriptapi.cpp
+++ b/src/mainwindow_scriptapi.cpp
@@ -176,7 +176,7 @@ int MainWindow::getHeight() {
 void MainWindow::setDimensions(int width, int height) {
     if (!this->editor || !this->editor->map)
         return;
-    if (!MainWindow::mapDimensionsValid(width, height))
+    if (!Project::mapDimensionsValid(width, height))
         return;
     this->editor->map->setDimensions(width, height);
     this->editor->map->commit();
@@ -186,7 +186,7 @@ void MainWindow::setDimensions(int width, int height) {
 void MainWindow::setWidth(int width) {
     if (!this->editor || !this->editor->map)
         return;
-    if (!MainWindow::mapDimensionsValid(width, this->editor->map->getHeight()))
+    if (!Project::mapDimensionsValid(width, this->editor->map->getHeight()))
         return;
     this->editor->map->setDimensions(width, this->editor->map->getHeight());
     this->editor->map->commit();
@@ -196,7 +196,7 @@ void MainWindow::setWidth(int width) {
 void MainWindow::setHeight(int height) {
     if (!this->editor || !this->editor->map)
         return;
-    if (!MainWindow::mapDimensionsValid(this->editor->map->getWidth(), height))
+    if (!Project::mapDimensionsValid(this->editor->map->getWidth(), height))
         return;
     this->editor->map->setDimensions(this->editor->map->getWidth(), height);
     this->editor->map->commit();
diff --git a/src/project.cpp b/src/project.cpp
index fecc2a05..c5c1504b 100644
--- a/src/project.cpp
+++ b/src/project.cpp
@@ -2046,7 +2046,7 @@ QMap<QString, QStringList> Project::getTilesetLabels() {
 
 bool Project::readTilesetProperties() {
     QStringList definePrefixes;
-    definePrefixes << "NUM_" << "MAX_";
+    definePrefixes << "NUM_";
     QString filename = "include/fieldmap.h";
     fileWatcher.addPath(root + "/" + filename);
     QMap<QString, int> defines = parser.readCDefines(filename, definePrefixes);
@@ -2099,7 +2099,16 @@ bool Project::readTilesetProperties() {
         logWarn(QString("Value for tileset property 'NUM_PALS_TOTAL' not found. Using default (%1) instead.")
                 .arg(Project::num_pals_total));
     }
-    it = defines.find("MAX_MAP_DATA_SIZE");
+    return true;
+}
+
+bool Project::readMaxMapDataSize() {
+    QStringList definePrefixes;
+    definePrefixes << "MAX_";
+    QString filename = "include/fieldmap.h"; // already in fileWatcher from readTilesetProperties
+    QMap<QString, int> defines = parser.readCDefines(filename, definePrefixes);
+
+    auto it = defines.find("MAX_MAP_DATA_SIZE");
     if (it != defines.end()) {
         int min = getMapDataSize(1, 1);
         if (it.value() >= min) {
@@ -2588,6 +2597,10 @@ int Project::getMaxMapHeight()
     return (getMaxMapDataSize() / (1 + 15)) - 14;
 }
 
+bool Project::mapDimensionsValid(int width, int height) {
+    return getMapDataSize(width, height) <= getMaxMapDataSize();
+}
+
 // Get largest possible square dimensions for a map up to maximum of 20x20 (arbitrary)
 bool Project::calculateDefaultMapSize(){
     int max = getMaxMapDataSize();