1 files changed, 1 insertions, 1 deletions
diff --git a/src/render/shadergraph/qshadergenerator.cpp b/src/render/shadergraph/qshadergenerator.cpp
index 96e80312a..48c7b37d1 100644
--- a/src/render/shadergraph/qshadergenerator.cpp
+++ b/src/render/shadergraph/qshadergenerator.cpp
@@ -616,7 +616,7 @@ QByteArray QShaderGenerator::createShaderCode(const QStringList &enabledLayers)
             qsizetype end = begin + 1;
             char endChar = line.at(end);
             const qsizetype size = line.size();
-            while (end < size && (std::isalnum(endChar) || endChar == '_')) {
+            while (end < size && (std::isalnum(uchar(endChar)) || endChar == '_')) {
                 ++end;
                 endChar = line.at(end);
             }