--- a/pg_main.c
+++ b/pg_main.c
@@ -28,7 +28,8 @@
 
 // globals
 
-#define MemoryContextResetAndDeleteChildren(...)
+// PG17 dropped this macro; the no-op stub leaked every message's parse/plan state.
+#define MemoryContextResetAndDeleteChildren(ctx) MemoryContextReset(ctx)
 // #define SpinLockInit(...)