diff --git a/Pdf4QtLibCore/sources/pdfannotation.cpp b/Pdf4QtLibCore/sources/pdfannotation.cpp
index 9466c01..8034779 100644
--- a/Pdf4QtLibCore/sources/pdfannotation.cpp
+++ b/Pdf4QtLibCore/sources/pdfannotation.cpp
@@ -2646,7 +2646,7 @@ PDFAnnotationDefaultAppearance PDFAnnotationDefaultAppearance::parse(const QByte
 
     auto readNumber = [&tokens](size_t index) -> PDFReal
     {
-        Q_ASSERT(index >= 0 && index < tokens.size());
+        Q_ASSERT(index < tokens.size());
         const PDFLexicalAnalyzer::Token& token = tokens[index];
         if (token.type == PDFLexicalAnalyzer::TokenType::Real ||
             token.type == PDFLexicalAnalyzer::TokenType::Integer)
diff --git a/Pdf4QtLibCore/sources/pdfdiff.cpp b/Pdf4QtLibCore/sources/pdfdiff.cpp
index 165fc2d..970cc86 100644
--- a/Pdf4QtLibCore/sources/pdfdiff.cpp
+++ b/Pdf4QtLibCore/sources/pdfdiff.cpp
@@ -1814,7 +1814,7 @@ void PDFDiffResultNavigator::setResult(const PDFDiffResult* diffResult)
 bool PDFDiffResultNavigator::isSelected() const
 {
     const size_t limit = getLimit();
-    return m_currentIndex >= 0 && m_currentIndex < limit;
+    return m_currentIndex < limit;
 }
 
 bool PDFDiffResultNavigator::canGoNext() const