diff --git a/source/ast/symbols/ValueSymbol.cpp b/source/ast/symbols/ValueSymbol.cpp
index e803419d3..f03a77e4f 100644
--- a/source/ast/symbols/ValueSymbol.cpp
+++ b/source/ast/symbols/ValueSymbol.cpp
@@ -445,7 +445,7 @@ std::optional<DriverBitRange> ValueDriver::getBounds(const Expression& prefixExp
                 return std::nullopt;
 
             SLANG_ASSERT(elemRange->left >= 0 && elemRange->right >= 0);
-            start = elemRange->lower();
+            start = (uint64_t)elemRange->lower();
             width = elemRange->width();
         }