diff --git a/java/gen.go b/java/gen.go
index 69965ec..c9cabc8 100644
--- a/java/gen.go
+++ b/java/gen.go
@@ -65,10 +65,6 @@
 func genAidl(ctx android.ModuleContext, aidlFile android.Path, aidlFlags string, deps android.Paths) android.Path {
 	javaFile := android.GenPathWithExt(ctx, "aidl", aidlFile, "java")
 	depFile := javaFile.String() + ".d"
-	baseDir := strings.TrimSuffix(aidlFile.String(), aidlFile.Rel())
-	if baseDir != "" {
-		aidlFlags += " -I" + baseDir
-	}
 
 	ctx.Build(pctx, android.BuildParams{
 		Rule:        aidl,
@@ -111,15 +107,30 @@
 	return srcJarFile
 }
 
+func genAidlIncludeFlags(srcFiles android.Paths) string {
+	var baseDirs []string
+	for _, srcFile := range srcFiles {
+		if srcFile.Ext() == ".aidl" {
+			baseDir := strings.TrimSuffix(srcFile.String(), srcFile.Rel())
+			if baseDir != "" && !android.InList(baseDir, baseDirs) {
+				baseDirs = append(baseDirs, baseDir)
+			}
+		}
+	}
+	return android.JoinWithPrefix(baseDirs, " -I")
+}
+
 func (j *Module) genSources(ctx android.ModuleContext, srcFiles android.Paths,
 	flags javaBuilderFlags) android.Paths {
 
 	outSrcFiles := make(android.Paths, 0, len(srcFiles))
 
+	aidlIncludeFlags := genAidlIncludeFlags(srcFiles)
+
 	for _, srcFile := range srcFiles {
 		switch srcFile.Ext() {
 		case ".aidl":
-			javaFile := genAidl(ctx, srcFile, flags.aidlFlags, flags.aidlDeps)
+			javaFile := genAidl(ctx, srcFile, flags.aidlFlags+aidlIncludeFlags, flags.aidlDeps)
 			outSrcFiles = append(outSrcFiles, javaFile)
 		case ".logtags":
 			j.logtagsSrcs = append(j.logtagsSrcs, srcFile)