diff --git a/core/java/com/android/internal/widget/LockPatternView.java b/core/java/com/android/internal/widget/LockPatternView.java
index 53be891..bad7292 100644
--- a/core/java/com/android/internal/widget/LockPatternView.java
+++ b/core/java/com/android/internal/widget/LockPatternView.java
@@ -582,6 +582,8 @@
                     mInProgressY = y;
 
                     if (mPatternInProgress) {
+                        if (mPattern.isEmpty()) return false;
+
                         final ArrayList<Cell> pattern = mPattern;
                         final float radius = mSquareWidth * mDiameterFactor * 0.5f;