diff --git a/libitm/ChangeLog b/libitm/ChangeLog
index 9c70974776c..37a1b443e11 100644
--- a/libitm/ChangeLog
+++ b/libitm/ChangeLog
@@ -1,3 +1,8 @@
+2020-05-05  Nathan Sidwell  <nathan@acm.org>
+
+	* testsuite/lib/libitm.exp (libitm_init): Add
+	-fdiagnostics-color=never to options.
+
 2020-02-12  Sandra Loosemore  <sandra@codesourcery.com>
 
 	PR libstdc++/79193
diff --git a/libitm/testsuite/lib/libitm.exp b/libitm/testsuite/lib/libitm.exp
index b3d247b9f98..6d8e3e71310 100644
--- a/libitm/testsuite/lib/libitm.exp
+++ b/libitm/testsuite/lib/libitm.exp
@@ -175,6 +175,8 @@ proc libitm_init { args } {
 
     # Turn on transactional memory support.
     lappend ALWAYS_CFLAGS "additional_flags=-fgnu-tm"
+
+    lappend ALWAYS_CFLAGS "additional_flags=-fdiagnostics-color=never"
 }
 
 #