diff --git a/java/base.go b/java/base.go
index 2e77c1e..85f4a5e 100644
--- a/java/base.go
+++ b/java/base.go
@@ -1003,7 +1003,7 @@
 					topLevelDirs[srcFileParts[0]] = true
 				}
 			}
-			patchPaths = append(patchPaths, android.SortedStringKeys(topLevelDirs)...)
+			patchPaths = append(patchPaths, android.SortedKeys(topLevelDirs)...)
 
 			classPath := flags.classpath.FormJavaClassPath("")
 			if classPath != "" {