diff --git a/local/recipes/qt/qtdeclarative/recipe.toml b/local/recipes/qt/qtdeclarative/recipe.toml
index 456a3ffb66..f585fab976 100644
--- a/local/recipes/qt/qtdeclarative/recipe.toml
+++ b/local/recipes/qt/qtdeclarative/recipe.toml
@@ -148,6 +148,18 @@ fi
 rm -f CMakeCache.txt
 rm -rf CMakeFiles
 
+# Remove stale qlalr-generated grammar. The QML lexer/parser grammar
+# (qqmljsgrammar_p.h + qqmljsgrammar.cpp) is generated by qt_process_qlalr from
+# src/qml/parser/qqmljs.g; the source ships none. An incremental rebuild (e.g.
+# after a relibc ABI change invalidates the fingerprint) can leave a 1-line empty
+# stub that survives CMakeCache/CMakeFiles removal, so ninja considers it up to
+# date and skips regeneration — every consumer of qqmljslexer_p.h then fails with
+# "expected class-name" / "QQmlJS::Parser has incomplete type". Deleting the
+# stale outputs forces qt_process_qlalr to regenerate them (missing output ->
+# rule re-runs). This is pattern (j): stale codegen after a toolchain rebuild.
+find . -name 'qqmljsgrammar_p.h' -delete 2>/dev/null || true
+find . -name 'qqmljsgrammar.cpp' -delete 2>/dev/null || true
+
 redbear_qt_link_sysroot_dirs "${COOKBOOK_SYSROOT}" plugins mkspecs metatypes modules qml
 
 # Patch masm/CheckedArithmetic.h: add missing ArithmeticOperations<unsigned, long>