diff --git a/qa/cephfs/begin/3-kernel.yaml b/qa/cephfs/begin/3-kernel.yaml
new file mode 100644
index 00000000000000..685c744a71e71e
--- /dev/null
+++ b/qa/cephfs/begin/3-kernel.yaml
@@ -0,0 +1,17 @@
+# When the --kernel option is given to teuthology-suite, the "default" kernel
+# is set for all nodes. We don't generally want to use a custom kernel for all
+# tests, so unset it. The k-testing.yaml will set it, if given, for only the
+# client nodes.
+#
+# Allow overriding this by using a branch ending in "-all".
+
+teuthology:
+  postmerge:
+    - |
+      if not yaml.kernel.branch:find "-all$" then
+        log.debug("removing default kernel specification: %s", yaml.kernel)
+        py_attrgetter(yaml.kernel).pop('branch', nil)
+        py_attrgetter(yaml.kernel).pop('flavor', nil)
+        py_attrgetter(yaml.kernel).pop('kdb', nil)
+        py_attrgetter(yaml.kernel).pop('sha1', nil)
+      end
diff --git a/qa/cephfs/mount/kclient/overrides/distro/testing/k-testing.yaml b/qa/cephfs/mount/kclient/overrides/distro/testing/k-testing.yaml
index 2ee219125e7a7e..048cd5ce8b9049 100644
--- a/qa/cephfs/mount/kclient/overrides/distro/testing/k-testing.yaml
+++ b/qa/cephfs/mount/kclient/overrides/distro/testing/k-testing.yaml
@@ -1,3 +1,12 @@
+teuthology:
+  premerge: |
+    log.debug("base kernel %s", base_config.kernel)
+    local kernel = base_config.kernel
+    if kernel.branch ~= "distro" then
+      log.debug("overriding testing kernel with %s", kernel)
+      yaml_fragment.kernel.client = kernel
+    end
+
 kernel:
   client:
     branch: testing