diff --git a/pdfbox/src/main/java/org/apache/pdfbox/pdmodel/PDPageTree.java b/pdfbox/src/main/java/org/apache/pdfbox/pdmodel/PDPageTree.java
index 81404e904d2..79e274a924d 100644
--- a/pdfbox/src/main/java/org/apache/pdfbox/pdmodel/PDPageTree.java
+++ b/pdfbox/src/main/java/org/apache/pdfbox/pdmodel/PDPageTree.java
@@ -309,6 +309,7 @@ private COSDictionary get(int pageNum, COSDictionary node, int encountered)
     {
         if (pageNum < 1)
         {
+            pageSet.clear();
             throw new IndexOutOfBoundsException("Index out of bounds: " + pageNum);
         }
         if (pageSet.contains(node))
@@ -357,10 +358,12 @@ private COSDictionary get(int pageNum, COSDictionary node, int encountered)
                     }
                 }
 
+                pageSet.clear();
                 throw new IllegalStateException("1-based index not found: " + pageNum);
             }
             else
             {
+                pageSet.clear();
                 throw new IndexOutOfBoundsException("1-based index out of bounds: " + pageNum);
             }
         }
@@ -373,6 +376,7 @@ private COSDictionary get(int pageNum, COSDictionary node, int encountered)
             }
             else
             {
+                pageSet.clear();
                 throw new IllegalStateException("1-based index not found: " + pageNum);
             }
         }
diff --git a/pdfbox/src/test/java/org/apache/pdfbox/pdmodel/TestPDPageTree.java b/pdfbox/src/test/java/org/apache/pdfbox/pdmodel/TestPDPageTree.java
index 0dbe00a6022..5378e44763a 100644
--- a/pdfbox/src/test/java/org/apache/pdfbox/pdmodel/TestPDPageTree.java
+++ b/pdfbox/src/test/java/org/apache/pdfbox/pdmodel/TestPDPageTree.java
@@ -18,6 +18,8 @@
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertSame;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 import java.io.IOException;
 
@@ -133,6 +135,20 @@ void testInsertAfterBlankPage() throws IOException
         }
     }
 
+    @Test
+    void getValidPageAfterOutOfBoundsLookup() throws IOException
+    {
+        try (PDDocument document = new PDDocument())
+        {
+            PDPage page = new PDPage();
+            document.addPage(page);
+            PDPageTree pages = document.getPages();
+
+            assertThrows(IndexOutOfBoundsException.class, () -> pages.get(1));
+            assertSame(page.getCOSObject(), pages.get(0).getCOSObject());
+        }
+    }
+
     /**
      * PDFBOX-6040: avoid loop in getInheritableAttribute().
      *