diff --git a/CHANGES b/CHANGES
index 92ca10fc..1666dff6 100644
--- a/CHANGES
+++ b/CHANGES
@@ -22,6 +22,7 @@
 - Fixed UI navigation cursor not updating when switching between controller and mouse
 - Fixed DesktopPlayerData not ensuring data directory exists when writing JSON or binary files
 - Fixed Sprite not carrying over flip status from TextureRegion
+- Fixed out of bounds error when TextBox is set to value smaller than previous value
 - (#79) Add isInterpolateRequired() to collision classes
 
 [1.8.2]
diff --git a/ui/src/main/java/org/mini2Dx/ui/element/TextBox.java b/ui/src/main/java/org/mini2Dx/ui/element/TextBox.java
index c1b930d9..ccc1ebd5 100644
--- a/ui/src/main/java/org/mini2Dx/ui/element/TextBox.java
+++ b/ui/src/main/java/org/mini2Dx/ui/element/TextBox.java
@@ -24,6 +24,7 @@
 import org.mini2Dx.ui.layout.*;
 import org.mini2Dx.ui.listener.ActionListener;
 import org.mini2Dx.ui.listener.TextInputListener;
+import org.mini2Dx.ui.render.NodeState;
 import org.mini2Dx.ui.render.ParentRenderNode;
 import org.mini2Dx.ui.render.TextBoxRenderNode;
 import org.mini2Dx.ui.render.UiContainerRenderTree;
@@ -293,6 +294,7 @@ public boolean grabInput(UiContainer uiContainer) {
 			return false;
 		}
 		uiContainer.setActiveAction(renderNode);
+		renderNode.setState(NodeState.ACTION);
 		return true;
 	}
 
diff --git a/ui/src/main/java/org/mini2Dx/ui/render/TextBoxRenderNode.java b/ui/src/main/java/org/mini2Dx/ui/render/TextBoxRenderNode.java
index 701a5223..00f13829 100644
--- a/ui/src/main/java/org/mini2Dx/ui/render/TextBoxRenderNode.java
+++ b/ui/src/main/java/org/mini2Dx/ui/render/TextBoxRenderNode.java
@@ -82,6 +82,10 @@ public void update(UiContainerRenderTree uiContainer, float delta) {
 		if (cursorTimer <= 0f) {
 			cursorTimer += CURSOR_VISIBLE_DURATION * 2f;
 		}
+		if (cursor > element.getValue().length()) {
+			cursor = element.getValue().length();
+			setCursorRenderX();
+		}
 		cursorTimer -= delta;
 	}