diff --git a/cyrus-imapd.spec b/cyrus-imapd.spec
index f93ca40..f6c78b1 100644
--- a/cyrus-imapd.spec
+++ b/cyrus-imapd.spec
@@ -421,28 +421,27 @@ mkdir -p imaptest/src
 ln -s /usr/bin/imaptest imaptest/src
 ln -s /usr/share/imaptest/tests imaptest/src
 
-
-# Build the syslog interposer
-gcc -fPIC -shared -Wl,-soname,-libredirectsyslog.so.0 -ldl -o libredirectsyslog.so.0.0 redirect-syslog.c
+# Build the syslog interposer; not currently working
+#gcc -fPIC -shared -Wl,-soname,-libredirectsyslog.so.0 -ldl -o libredirectsyslog.so.0.0 redirect-syslog.c
 
 export LD_LIBRARY_PATH=%buildroot/%_libdir
 export CYRUS_USER=$USER
 
-# Most Cassandane tests pass, but using snapshots includes new tests which
-# aren't supposed to pass on released versions of cyrus.  So we have a big
-# exclusion list.
-
+# Construct the set of excluded tests to pass to Cassandane
+# ---------------------------------------------------------
 # Note that Cassandane::Test::Core must always be excluded; it can't possibly
-# work.  The others are expected on 3.0.1 and should be removed and re-checked
-# at each release.
-exclude=('!Cassandane::Test::Core')
+# work.
+# Upstream says that the Metronome tests won't be reliable on shared hardware
+# and are more for testing system performance than for testing Cyrus itself.
+exclude=('!Cassandane::Test::Core' '!Metronome')
 
+# The below non-arch-specific excluded tests are expected to fail n 3.0.1 and
+# should be removed and re-checked at each release.
 tests=(
     Admin.imap_admins Fetch.fetch_flags_before_exists  Quota.num_folders_rename
     SearchFuzzy.cjk_words SearchFuzzy.xattachmentname
 )
 for i in ${tests[@]}; do exclude+=("!$i"); done
-
 tests=(
     creationids
     getcalendareventlist
@@ -475,7 +474,6 @@ tests=(
     setcalendarevents_simple
 )
 for i in ${tests[@]}; do exclude+=("!JMAPCalendars.$i"); done
-
 tests=(
     getmessagelist_attachments
     getmessagelist_window
@@ -499,13 +497,18 @@ for i in ${tests[@]}; do exclude+=("!$i"); done
 %endif
 
 %ifarch s390x
-exclude+=("!Master.maxforkrate") # Our s390x hosts are too slow to complete this test properly
+# This one test fails occasionally on s390x because the hosts are just too slow
+# to complete it.  It's testing something valid (that the fork rate limiting
+# settings work properly) but s399x can'f fork quickly enough to exceeed the
+# limits it's testing.
+exclude+=("!Master.maxforkrate")
 %endif
 
 %ifarch i686 armv7hl
 # Some additional failures only on 32-bit machines.
 # 14 failures are due to Fedora's perl not supporting quad types in unpack.
-# This is due to be fixed in rawhide soon, so some of these can go away.
+# This is due to be fixed in rawhide soon, so some of these can go away but
+# only on rawhide, not F26.
 tests=(
     JMAPContacts.setcontacts_importance_later
     Metadata.expunge_messages
@@ -630,6 +633,8 @@ getent passwd cyrus >/dev/null || /usr/sbin/useradd -c "Cyrus IMAP Server" -d /v
 - Use proper path to ctl_mboxlist in cron file.
 - Add patch to increase individual test timeout.  Sometimes armv7hl can't
   complete a single test in 20 seconds.
+- Disable the Metronome tests; upstream says that they just won't reliably on
+  shared hardware.
 
 * Tue Jun 06 2017 Jitka Plesnikova <jplesnik@redhat.com> - 3.0.1-4
 - Perl 5.26 rebuild