diff --git a/pkg/diag/diag.go b/pkg/diag/diag.go
index c1f3a0a..df4b83d 100644
--- a/pkg/diag/diag.go
+++ b/pkg/diag/diag.go
@@ -179,7 +179,10 @@ func (d *Diag) CheckCRI(scope []string) CheckResult {
 	missing := []string{}
 	configured := []string{}
 	for _, name := range scope {
-		handler := d.handlerFor(name)
+		handler, err := d.handlerFor(name)
+		if err != nil {
+			return CheckResult{ID: "cri", Status: StatusWarn, Detail: fmt.Sprintf("cannot read the local store: %v", err)}
+		}
 		if cc.HasHandler(handler) {
 			configured = append(configured, handler)
 		} else {
@@ -210,17 +213,20 @@ func (d *Diag) CheckEvents() CheckResult {
 	return CheckResult{ID: "events", Status: StatusWarn, Detail: "reportEvent is false: pod failures may not surface as events. Enable edgeCore.reportEvent"}
 }
 
-func (d *Diag) handlerFor(name string) string {
+// handlerFor maps a class name to its handler from the local store. Classes
+// absent from the store fall back to the class name (the common naming
+// convention); a store read failure is returned instead of guessed at.
+func (d *Diag) handlerFor(name string) (string, error) {
 	classes, err := d.Store.ListRuntimeClasses()
 	if err != nil {
-		return name
+		return "", err
 	}
 	for _, c := range classes {
 		if c.Name == name && c.Handler != "" {
-			return c.Handler
+			return c.Handler, nil
 		}
 	}
-	return name
+	return name, nil
 }
 
 func lookupOutcome(handler string, err error) string {
diff --git a/pkg/diag/diag_test.go b/pkg/diag/diag_test.go
index 19ca4d2..2702f31 100644
--- a/pkg/diag/diag_test.go
+++ b/pkg/diag/diag_test.go
@@ -199,6 +199,16 @@ func TestCheckCRI(t *testing.T) {
 			t.Fatalf("expected warn, got %+v", res)
 		}
 	})
+	t.Run("warn when store unreadable", func(t *testing.T) {
+		d := withPaths(t, &Diag{Store: &fakeStore{err: errBoom}})
+		res := d.CheckCRI([]string{"kata"})
+		if res.Status != StatusWarn {
+			t.Fatalf("expected warn, got %+v", res)
+		}
+		if !strings.Contains(res.Detail, "local store") {
+			t.Fatalf("expected store error in detail, got %q", res.Detail)
+		}
+	})
 }
 
 func TestCheckEvents(t *testing.T) {