diff --git a/lib/valueflow.cpp b/lib/valueflow.cpp
index 37c2e4863f14..7e7cf5b9a813 100644
--- a/lib/valueflow.cpp
+++ b/lib/valueflow.cpp
@@ -606,7 +606,7 @@ static ValueFlow::Value truncateImplicitConversion(Token* parent, const ValueFlo
 
 static long long truncateIntValue(long long value, size_t value_size, const ValueType::Sign dst_sign)
 {
-    const MathLib::biguint unsignedMaxValue = std::numeric_limits<decltype(unsignedMaxValue)>::max() >> ((sizeof(unsignedMaxValue) - value_size) * 8);
+    const MathLib::biguint unsignedMaxValue = std::numeric_limits<decltype(unsignedMaxValue)>::max() >> (sizeof(unsignedMaxValue) != value_size ? ((sizeof(unsignedMaxValue) - value_size) * 8) : 0);
     const MathLib::biguint signBit = 1ULL << (value_size * 8 - 1);
     value &= unsignedMaxValue;
     if (dst_sign == ValueType::Sign::SIGNED && (value & signBit))