diff --git a/poi-ooxml/src/test/java/org/apache/poi/poifs/crypt/dsig/TestSignatureInfo.java b/poi-ooxml/src/test/java/org/apache/poi/poifs/crypt/dsig/TestSignatureInfo.java
index 932195193e..3a7e4eb5ed 100644
--- a/poi-ooxml/src/test/java/org/apache/poi/poifs/crypt/dsig/TestSignatureInfo.java
+++ b/poi-ooxml/src/test/java/org/apache/poi/poifs/crypt/dsig/TestSignatureInfo.java
@@ -252,7 +252,11 @@ class TestSignatureInfo {
             si.setOpcPackage(pkg);
             si.setSignatureConfig(sic);
             boolean isValid = si.verifySignature();
-            assertTrue(isValid);
+
+            assertTrue(isValid,
+                    // add some details to find out why "verifySignature()" returns false sometimes
+                    "Verifying signature failed, hasNext: " + si.getSignatureParts().iterator().hasNext() + ": " +
+                            (si.getSignatureParts().iterator().hasNext() ? si.getSignatureParts().iterator() : ""));
         }
     }