diff --git a/frontend/layout/lib/layoutModel.ts b/frontend/layout/lib/layoutModel.ts
index 70ed3db6..4243e606 100644
--- a/frontend/layout/lib/layoutModel.ts
+++ b/frontend/layout/lib/layoutModel.ts
@@ -46,6 +46,7 @@ interface ResizeContext {
 }
 
 const DefaultGapSizePx = 5;
+const MinNodeSizePx = 40;
 
 export class LayoutModel {
     /**
@@ -666,6 +667,15 @@ export class LayoutModel {
         const clientDiff = (this.resizeContext.resizeHandleStartPx - clientPoint) * this.resizeContext.pixelToSizeRatio;
         const beforeNodeSize = this.resizeContext.beforeNodeStartSize - clientDiff;
         const afterNodeSize = this.resizeContext.afterNodeStartSize + clientDiff;
+
+        // If either node will be too small after this resize, don't let it happen.
+        if (
+            beforeNodeSize / this.resizeContext.pixelToSizeRatio < MinNodeSizePx ||
+            afterNodeSize / this.resizeContext.pixelToSizeRatio < MinNodeSizePx
+        ) {
+            return;
+        }
+
         const resizeAction: LayoutTreeResizeNodeAction = {
             type: LayoutTreeActionType.ResizeNode,
             resizeOperations: [