diff --git a/source/numeric/SVInt.cpp b/source/numeric/SVInt.cpp
index 265353019..5b8bfbef0 100644
--- a/source/numeric/SVInt.cpp
+++ b/source/numeric/SVInt.cpp
@@ -640,8 +640,7 @@ std::ostream& operator<<(std::ostream& os, const SVInt& rhs) {
 std::string SVInt::toString(bitwidth_t abbreviateThresholdBits, bool exactUnknowns) const {
     // guess the base to use
     LiteralBase base;
-    // unless the int is wholly or digit/hexit-wise X or Z (TODO: worth checking?),
-    // unknown bits require binary base for lossless representation.
+    // unknown bits require binary base for lossless representation
     if (bitWidth < 8 || (unknownFlag && exactUnknowns) || (unknownFlag && bitWidth <= 64))
         base = LiteralBase::Binary;
     else if (bitWidth <= 32 || signFlag)