diff --git a/android/bazel_paths.go b/android/bazel_paths.go
index 9957369..23b2e7a 100644
--- a/android/bazel_paths.go
+++ b/android/bazel_paths.go
@@ -370,11 +370,17 @@
 
 func bazelShortLabel(label string) string {
 	i := strings.Index(label, ":")
+	if i == -1 {
+		panic(fmt.Errorf("Could not find the ':' character in '%s', expected a fully qualified label.", label))
+	}
 	return label[i:]
 }
 
 func bazelPackage(label string) string {
 	i := strings.Index(label, ":")
+	if i == -1 {
+		panic(fmt.Errorf("Could not find the ':' character in '%s', expected a fully qualified label.", label))
+	}
 	return label[0:i]
 }