diff --git a/android/writedocs.go b/android/writedocs.go
index 67b9aa3..c380a3d 100644
--- a/android/writedocs.go
+++ b/android/writedocs.go
@@ -34,12 +34,12 @@
 type docsSingleton struct{}
 
 func primaryBuilderPath(ctx SingletonContext) Path {
-	buildDir := absolutePath(ctx.Config().BuildDir())
+	soongOutDir := absolutePath(ctx.Config().SoongOutDir())
 	binary := absolutePath(os.Args[0])
-	primaryBuilder, err := filepath.Rel(buildDir, binary)
+	primaryBuilder, err := filepath.Rel(soongOutDir, binary)
 	if err != nil {
 		ctx.Errorf("path to primary builder %q is not in build dir %q (%q)",
-			os.Args[0], ctx.Config().BuildDir(), err)
+			os.Args[0], ctx.Config().SoongOutDir(), err)
 	}
 
 	return PathForOutput(ctx, primaryBuilder)