diff --git a/qa/suites/fs/verify/validater/valgrind.yaml b/qa/suites/fs/verify/validater/valgrind.yaml
index b3e2339821b3f..82a6574752f9e 100644
--- a/qa/suites/fs/verify/validater/valgrind.yaml
+++ b/qa/suites/fs/verify/validater/valgrind.yaml
@@ -5,6 +5,7 @@ overrides:
     log-whitelist:
       - slow requests are blocked
 
+os_type: centos   # xenial valgrind buggy, see http://tracker.ceph.com/issues/18126
 overrides:
   install:
     ceph:
diff --git a/qa/suites/rados/singleton-nomsgr/all/valgrind-leaks.yaml b/qa/suites/rados/singleton-nomsgr/all/valgrind-leaks.yaml
index fde0dbbe05b97..c05ad133be36a 100644
--- a/qa/suites/rados/singleton-nomsgr/all/valgrind-leaks.yaml
+++ b/qa/suites/rados/singleton-nomsgr/all/valgrind-leaks.yaml
@@ -1,3 +1,4 @@
+os_type: centos   # xenial valgrind buggy, see http://tracker.ceph.com/issues/18126
 overrides:
   install:
     ceph:
diff --git a/qa/suites/rados/verify/validater/valgrind.yaml b/qa/suites/rados/verify/validater/valgrind.yaml
index dc63731b1d2c4..ef5ef7bd7b5d2 100644
--- a/qa/suites/rados/verify/validater/valgrind.yaml
+++ b/qa/suites/rados/verify/validater/valgrind.yaml
@@ -1,3 +1,4 @@
+os_type: centos   # xenial valgrind buggy, see http://tracker.ceph.com/issues/18126
 overrides:
   install:
     ceph:
diff --git a/qa/suites/rbd/valgrind/validator/memcheck.yaml b/qa/suites/rbd/valgrind/validator/memcheck.yaml
index b8d328e8c0823..c5348269a89b2 100644
--- a/qa/suites/rbd/valgrind/validator/memcheck.yaml
+++ b/qa/suites/rbd/valgrind/validator/memcheck.yaml
@@ -1,3 +1,4 @@
+os_type: centos   # xenial valgrind buggy, see http://tracker.ceph.com/issues/18126
 overrides:
   install:
     ceph:
diff --git a/qa/suites/rgw/multisite/valgrind.yaml b/qa/suites/rgw/multisite/valgrind.yaml
index 0b28c18306508..1e17c783a0795 100644
--- a/qa/suites/rgw/multisite/valgrind.yaml
+++ b/qa/suites/rgw/multisite/valgrind.yaml
@@ -1,3 +1,4 @@
+os_type: centos   # xenial valgrind buggy, see http://tracker.ceph.com/issues/18126
 overrides:
   install:
     ceph:
diff --git a/qa/suites/rgw/verify/tasks/rgw_s3tests.yaml b/qa/suites/rgw/verify/tasks/rgw_s3tests.yaml
index 851b67be6c6a6..6d3c1370b4add 100644
--- a/qa/suites/rgw/verify/tasks/rgw_s3tests.yaml
+++ b/qa/suites/rgw/verify/tasks/rgw_s3tests.yaml
@@ -1,3 +1,4 @@
+os_type: centos   # xenial valgrind buggy, see http://tracker.ceph.com/issues/18126
 tasks:
 - install:
     flavor: notcmalloc
diff --git a/qa/suites/rgw/verify/tasks/rgw_swift.yaml b/qa/suites/rgw/verify/tasks/rgw_swift.yaml
index 792fb848a9ebc..6e6e9eee636fd 100644
--- a/qa/suites/rgw/verify/tasks/rgw_swift.yaml
+++ b/qa/suites/rgw/verify/tasks/rgw_swift.yaml
@@ -1,3 +1,4 @@
+os_type: centos   # xenial valgrind buggy, see http://tracker.ceph.com/issues/18126
 tasks:
 - install:
     flavor: notcmalloc
diff --git a/qa/suites/rgw/verify/validater/valgrind.yaml b/qa/suites/rgw/verify/validater/valgrind.yaml
index dc63731b1d2c4..ef5ef7bd7b5d2 100644
--- a/qa/suites/rgw/verify/validater/valgrind.yaml
+++ b/qa/suites/rgw/verify/validater/valgrind.yaml
@@ -1,3 +1,4 @@
+os_type: centos   # xenial valgrind buggy, see http://tracker.ceph.com/issues/18126
 overrides:
   install:
     ceph: