diff --git a/config/mh-cygwin32 b/config/mh-cygwin32
index a798f8b060..2d7035ec11 100644
--- a/config/mh-cygwin32
+++ b/config/mh-cygwin32
@@ -1,3 +1,7 @@
+# We don't want debugging info in Win32-hosted toolchains.
+# Accomplish this by overriding CFLAGS.
+CFLAGS=-O2
+
 # We set MAKEINFOFLAGS to not split .info files, because the resulting
 # file names don't work on DOS.
 MAKEINFOFLAGS=--no-split