diff --git a/poi/src/main/java/org/apache/poi/hssf/record/TextObjectRecord.java b/poi/src/main/java/org/apache/poi/hssf/record/TextObjectRecord.java
index c399bd64f9..17bcce71e7 100644
--- a/poi/src/main/java/org/apache/poi/hssf/record/TextObjectRecord.java
+++ b/poi/src/main/java/org/apache/poi/hssf/record/TextObjectRecord.java
@@ -127,6 +127,9 @@ public final class TextObjectRecord extends ContinuableRecord {
                 throw new RecordFormatException("Read " + ptgs.length
                         + " tokens but expected exactly 1");
             }
+            if (!(ptgs[0] instanceof OperandPtg)) {
+                throw new IllegalArgumentException("Had unexpected type of ptg at index 0: " + ptgs[0].getClass());
+            }
             _linkRefPtg = (OperandPtg) ptgs[0];
             _unknownPostFormulaByte = in.remaining() > 0 ? in.readByte() : null;
         } else {
diff --git a/poi/src/test/java/org/apache/poi/hssf/dev/BaseTestIteratingXLS.java b/poi/src/test/java/org/apache/poi/hssf/dev/BaseTestIteratingXLS.java
index 45de3c2155..26627b5a9b 100644
--- a/poi/src/test/java/org/apache/poi/hssf/dev/BaseTestIteratingXLS.java
+++ b/poi/src/test/java/org/apache/poi/hssf/dev/BaseTestIteratingXLS.java
@@ -86,6 +86,8 @@ public abstract class BaseTestIteratingXLS {
         excludes.put("61300.xls", RecordFormatException.class);
         // BIFF 5
         excludes.put("64130.xls", OldExcelFormatException.class);
+        // fuzzed binaries
+        excludes.put("clusterfuzz-testcase-minimized-POIHSSFFuzzer-6322470200934400.xls", RuntimeException.class);
         return excludes;
     }
 
diff --git a/test-data/spreadsheet/clusterfuzz-testcase-minimized-POIHSSFFuzzer-6322470200934400.xls b/test-data/spreadsheet/clusterfuzz-testcase-minimized-POIHSSFFuzzer-6322470200934400.xls
new file mode 100644
index 0000000000..40f4ecaeae
Binary files /dev/null and b/test-data/spreadsheet/clusterfuzz-testcase-minimized-POIHSSFFuzzer-6322470200934400.xls differ
diff --git a/test-data/spreadsheet/stress.xls b/test-data/spreadsheet/stress.xls
index 70847a482c..cf344f0b84 100644
Binary files a/test-data/spreadsheet/stress.xls and b/test-data/spreadsheet/stress.xls differ