diff --git a/source/ast/symbols/MemberSymbols.cpp b/source/ast/symbols/MemberSymbols.cpp
index 5ada1ae1a..e4ae5a3e0 100644
--- a/source/ast/symbols/MemberSymbols.cpp
+++ b/source/ast/symbols/MemberSymbols.cpp
@@ -1421,7 +1421,7 @@ PrimitiveSymbol& PrimitiveSymbol::fromSyntax(const Scope& scope,
                             }
                         }
                         else {
-                            size_t nextPos = (state.at(i + 1) != '?')
+                            size_t nextPos = (size_t)(state.at(i + 1) != '?')
                                                  ? std::distance(edgeScope.begin(),
                                                                  std::find(edgeScope.begin(),
                                                                            edgeScope.end(),