diff --git a/expat/Changes b/expat/Changes
index aa19f70a..82e2f663 100644
--- a/expat/Changes
+++ b/expat/Changes
@@ -46,6 +46,8 @@ Release 2.6.4 Wed November 6 2024
             #904  tests: Resolve duplicate handler
        #317 #918  tests: Improve tests on doctype closing (ex CVE-2019-15903)
             #914  Fix signedness of format strings
+            #915  For use from C++, expat.h started requiring C++11 due to
+                    use of C99 features
        #919 #920  Version info bumped from 10:3:9 (libexpat*.so.1.9.3)
                     to 11:0:10 (libexpat*.so.1.10.0); see https://verbump.de/
                     for what these numbers do
diff --git a/expat/README.md b/expat/README.md
index 23d26dad..6076d16a 100644
--- a/expat/README.md
+++ b/expat/README.md
@@ -22,9 +22,9 @@ are called when the parser discovers the associated structures in the
 document being parsed.  A start tag is an example of the kind of
 structures for which you may register handlers.
 
-Expat supports the following compilers:
+Expat supports the following C99 compilers:
 
-- GNU GCC >=4.5
+- GNU GCC >=4.5 (for use from C) or GNU GCC >=4.8.1 (for use from C++)
 - LLVM Clang >=3.5
 - Microsoft Visual Studio >=16.0/2019 (rolling `${today} minus 5 years`)