diff --git a/include/core/metatile.h b/include/core/metatile.h
index 0b4b8a60..f606dcdb 100644
--- a/include/core/metatile.h
+++ b/include/core/metatile.h
@@ -8,6 +8,8 @@
 #include <QPoint>
 #include <QString>
 
+class Project;
+
 enum {
     METATILE_LAYER_MIDDLE_TOP,
     METATILE_LAYER_BOTTOM_MIDDLE,
@@ -91,7 +93,7 @@ public:
     static int getIndexInTileset(int);
     static QPoint coordFromPixmapCoord(const QPointF &pixelCoord);
     static int getDefaultAttributesSize(BaseGameVersion version);
-    static void setCustomLayout();
+    static void setCustomLayout(Project*);
 
 private:
     // Stores how each attribute should be laid out for all metatiles, according to the user's config
diff --git a/include/ui/tileseteditor.h b/include/ui/tileseteditor.h
index e671564f..fcdd3bed 100644
--- a/include/ui/tileseteditor.h
+++ b/include/ui/tileseteditor.h
@@ -85,7 +85,7 @@ private slots:
 
     void on_actionRedo_triggered();
 
-    void on_comboBox_metatileBehaviors_textActivated(const QString &arg1);
+    void on_comboBox_metatileBehaviors_currentTextChanged(const QString &arg1);
 
     void on_lineEdit_metatileLabel_editingFinished();
 
diff --git a/src/core/metatile.cpp b/src/core/metatile.cpp
index d48fbbac..160b0c42 100644
--- a/src/core/metatile.cpp
+++ b/src/core/metatile.cpp
@@ -95,7 +95,7 @@ bool Metatile::isMaskTooSmall(MetatileAttr * attr, int max) {
     uint32_t n = log2(max);
 
     // Get a mask for all values 0 to max.
-    // This may fail for n=31, but that's not a concern here.
+    // This may fail for n > 30, but that's not possible here.
     uint32_t rangeMask = (1 << (n + 1)) - 1;
 
     return attr->getClamped(rangeMask) != rangeMask;
@@ -110,7 +110,7 @@ bool Metatile::doMasksOverlap(QList<uint32_t> masks) {
     return false;
 }
 
-void Metatile::setCustomLayout() {
+void Metatile::setCustomLayout(Project * project) {
     // Get the maximum size of any attribute mask
     const QHash<int, uint32_t> maxMasks = {
         {1, 0xFF},
@@ -135,9 +135,13 @@ void Metatile::setCustomLayout() {
         logWarn("Metatile attribute masks are overlapping. This may result in unexpected attribute values.");
     }
 
-    // The available options in the Tileset Editor for Terrain Type, Encounter Type, and Layer Type are hard-coded.
-    // Warn the user if they have set a nonzero mask that is too small to contain these options.
-    // They'll be allowed to select them, but they'll be truncated to a different value when revisited.
+    // Warn the user if they have set a nonzero mask that is too small to contain its available options.
+    // They'll be allowed to select the options, but they'll be truncated to a different value when revisited.
+    if (!project->metatileBehaviorMapInverse.isEmpty()) {
+        int maxBehavior = project->metatileBehaviorMapInverse.lastKey();
+        if (isMaskTooSmall(&Metatile::behaviorAttr, maxBehavior))
+            logWarn(QString("Metatile Behavior mask is too small to contain all %1 available options.").arg(maxBehavior));
+    }
     if (isMaskTooSmall(&Metatile::terrainTypeAttr, NUM_METATILE_TERRAIN_TYPES - 1))
         logWarn(QString("Metatile Terrain Type mask is too small to contain all %1 available options.").arg(NUM_METATILE_TERRAIN_TYPES));
     if (isMaskTooSmall(&Metatile::encounterTypeAttr, NUM_METATILE_ENCOUNTER_TYPES - 1))
diff --git a/src/mainwindow.cpp b/src/mainwindow.cpp
index 2dc0dc0b..135b819f 100644
--- a/src/mainwindow.cpp
+++ b/src/mainwindow.cpp
@@ -505,7 +505,6 @@ bool MainWindow::openProject(QString dir) {
     userConfig.load();
     projectConfig.setProjectDir(dir);
     projectConfig.load();
-    Metatile::setCustomLayout();
 
     this->closeSupplementaryWindows();
     this->setProjectSpecificUIVisibility();
@@ -914,6 +913,7 @@ bool MainWindow::loadDataStructures() {
                 && project->readEventGraphics()
                 && project->readSongNames();
 
+    Metatile::setCustomLayout(project);
     Scripting::populateGlobalObject(this);
 
     return success && loadProjectCombos();
diff --git a/src/ui/tileseteditor.cpp b/src/ui/tileseteditor.cpp
index df130d5b..d45c65c7 100644
--- a/src/ui/tileseteditor.cpp
+++ b/src/ui/tileseteditor.cpp
@@ -503,11 +503,26 @@ void TilesetEditor::on_checkBox_yFlip_stateChanged(int checked)
     this->metatileLayersItem->clearLastModifiedCoords();
 }
 
-void TilesetEditor::on_comboBox_metatileBehaviors_textActivated(const QString &metatileBehavior)
+void TilesetEditor::on_comboBox_metatileBehaviors_currentTextChanged(const QString &metatileBehavior)
 {
     if (this->metatile) {
+        int behavior;
+        if (project->metatileBehaviorMap.contains(metatileBehavior)) {
+            behavior = project->metatileBehaviorMap[metatileBehavior];
+        } else {
+            // Check if user has entered a number value instead
+            bool ok;
+            behavior = metatileBehavior.toInt(&ok);
+            if (!ok) return;
+        }
+
+        // This function can also be called when the user selects
+        // a different metatile. Stop this from being considered a change.
+        if (this->metatile->behavior == static_cast<uint32_t>(behavior))
+            return;
+
         Metatile *prevMetatile = new Metatile(*this->metatile);
-        this->metatile->setBehavior(project->metatileBehaviorMap[metatileBehavior]);
+        this->metatile->setBehavior(behavior);
         MetatileHistoryItem *commit = new MetatileHistoryItem(this->getSelectedMetatileId(),
                                                               prevMetatile, new Metatile(*this->metatile));
         metatileHistory.push(commit);