diff --git a/configure.ac b/configure.ac
index b31ed24..a208889 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2694,6 +2694,8 @@
 		# Issue #18075: the default maximum stack size (8MBytes) is too
 		# small for the default recursion limit. Increase the stack size
 		# to ensure that tests don't crash
+		# Note: This matches the value of THREAD_STACK_SIZE in
+		# thread_pthread.h
 		LINKFORSHARED="-Wl,-stack_size,1000000 $LINKFORSHARED"
 
 		if test "$enable_framework"