diff --git a/cmd/promtool/unittest.go b/cmd/promtool/unittest.go
index 26370f41b1..9f5ac09cc5 100644
--- a/cmd/promtool/unittest.go
+++ b/cmd/promtool/unittest.go
@@ -145,6 +145,9 @@ func resolveAndGlobFilepaths(baseDir string, utf *unitTestFile) error {
 		if err != nil {
 			return err
 		}
+		if len(m) <= 0 {
+			fmt.Fprintln(os.Stderr, "  WARNING: no file match pattern", rf)
+		}
 		globbedFiles = append(globbedFiles, m...)
 	}
 	utf.RuleFiles = globbedFiles