diff --git a/source/preprocessor.tex b/source/preprocessor.tex
index 3e28b5dd9b..1152d0b0d7 100644
--- a/source/preprocessor.tex
+++ b/source/preprocessor.tex
@@ -482,6 +482,7 @@
 \tcode{assume}                & \tcode{202207L} \\
 \tcode{deprecated}            & \tcode{201309L} \\
 \tcode{fallthrough}           & \tcode{201603L} \\
+\tcode{indeterminate}         & \tcode{202403L} \\
 \tcode{likely}                & \tcode{201803L} \\
 \tcode{maybe_unused}          & \tcode{201603L} \\
 \tcode{no_unique_address}     & \tcode{201803L} \\