diff --git a/inc/qcbor/qcbor_encode.h b/inc/qcbor/qcbor_encode.h
index 82ea6c0..f0b8d0e 100644
--- a/inc/qcbor/qcbor_encode.h
+++ b/inc/qcbor/qcbor_encode.h
@@ -1774,13 +1774,21 @@
 
 
 /**
- @brief Cancel a wrapping bstr.
-
- @param[in] pCtx              The encoding context to close of bstr wrapping in.
-
- This only works if nothing has been added into the wrapped byte string.
- If something has been added, this sets the TODO: error.
- **/
+ * @brief Cancel byte string wrapping.
+ *
+ * @param[in] pCtx       The encoding context to close of bstr wrapping in.
+ *
+ * This cancels QCBOREncode_BstrWrap() making tghe encoding as if it
+ * were never called.
+ *
+ * WARNING: This does no work on QCBOREncode_BstrWrapInMap()
+ * or QCBOREncode_BstrWrapInMapN() and there is no detection
+ * of this error.
+ *
+ * This only works if nothing has been added into the wrapped byte
+ * string.  If something has been added, this sets the error
+ * @ref QCBOR_ERR_CANNOT_CANCEL.
+ */
 void QCBOREncode_CancelBstrWrap(QCBOREncodeContext *pCtx);
 
 
diff --git a/src/qcbor_encode.c b/src/qcbor_encode.c
index 9c286a9..ea94026 100644
--- a/src/qcbor_encode.c
+++ b/src/qcbor_encode.c
@@ -918,6 +918,14 @@
          return;
       }
    }
+   /* QCBOREncode_CancelBstrWrap() can't correctly undo
+    * QCBOREncode_BstrWrapInMap() or QCBOREncode_BstrWrapInMapN(). It
+    * can't undo the labels they add. It also doesn't catch the error
+    * of using it this way.  QCBOREncode_CancelBstrWrap() is used
+    * infrequently and the the result is incorrect CBOR, not a
+    * security hole, so no extra code or state is added to handle this
+    * condition.
+    */
 #endif /* QCBOR_DISABLE_ENCODE_USAGE_GUARDS */
 
    Nesting_Decrease(&(pMe->nesting));
diff --git a/test/qcbor_encode_tests.c b/test/qcbor_encode_tests.c
index 99dd7b7..d2f9958 100644
--- a/test/qcbor_encode_tests.c
+++ b/test/qcbor_encode_tests.c
@@ -1746,8 +1746,9 @@
 static const uint8_t spExpectedTypeAndLen[] = {0x81, 0x58, 0x25};
 
 static const uint8_t spExpectedTypeAndLenXXX[] = {0x82, 0x19, 0x01, 0xC3, 0x18, 0x2A};
+
 /*
- Very basic bstr wrapping test
+ * bstr wrapping test
  */
 int BstrWrapTest()
 {
@@ -1807,7 +1808,6 @@
       return -7;
    }
 
-
    // Fourth test, cancelling a byte string
    QCBOREncode_Init(&EC, UsefulBuf_FROM_BYTE_ARRAY(spBigBuf));
 
@@ -1827,6 +1827,8 @@
       return -9;
    }
 
+   QCBORError uErr;
+#ifndef QCBOR_DISABLE_ENCODE_USAGE_GUARDS
    // Fifth test, failed cancelling
    QCBOREncode_Init(&EC, UsefulBuf_FROM_BYTE_ARRAY(spBigBuf));
 
@@ -1839,10 +1841,29 @@
 
    QCBOREncode_AddUInt64(&EC, 42);
    QCBOREncode_CloseArray(&EC);
-   QCBORError uErr = QCBOREncode_Finish(&EC, &Encoded);
+   uErr = QCBOREncode_Finish(&EC, &Encoded);
    if(uErr != QCBOR_ERR_CANNOT_CANCEL) {
       return -10;
    }
+#endif
+
+   // Sixth test, another cancel, but the error is not caught
+   // This use will produce unintended CBOR. The error
+   // is not caught because it would require tracking state
+   // for QCBOREncode_BstrWrapInMapN.
+   QCBOREncode_Init(&EC, UsefulBuf_FROM_BYTE_ARRAY(spBigBuf));
+
+   QCBOREncode_OpenMap(&EC);
+   QCBOREncode_AddUInt64ToMapN(&EC, 451, 88);
+
+   QCBOREncode_BstrWrapInMapN(&EC, 55);
+   QCBOREncode_CancelBstrWrap(&EC);
+
+   QCBOREncode_CloseMap(&EC);
+   uErr = QCBOREncode_Finish(&EC, &Encoded);
+   if(uErr != QCBOR_SUCCESS) {
+      return -11;
+   }
 
    return 0;
 }