diff --git a/lib/Target/README.txt b/lib/Target/README.txt
index 89ea9d0..aec8fd0 100644
--- a/lib/Target/README.txt
+++ b/lib/Target/README.txt
@@ -1644,3 +1644,10 @@
 See also PR4973
 
 //===---------------------------------------------------------------------===//
+
+IPSCCP is propagating elements of first class aggregates, but is not propagating
+the entire aggregate itself.  This leads it to miss opportunities, for example
+in test/Transforms/SCCP/ipsccp-basic.ll:test5b.
+
+//===---------------------------------------------------------------------===//
+