Merge "Use a timestamp file for preprocessed_ndk_headers."
diff --git a/android/androidmk.go b/android/androidmk.go
index d55cdca..f606522 100644
--- a/android/androidmk.go
+++ b/android/androidmk.go
@@ -175,19 +175,21 @@
 
 	if data.Custom != nil {
 		prefix := ""
-		switch amod.Os().Class {
-		case Host:
-			prefix = "HOST_"
-		case HostCross:
-			prefix = "HOST_CROSS_"
-		case Device:
-			prefix = "TARGET_"
+		if amod.ArchSpecific() {
+			switch amod.Os().Class {
+			case Host:
+				prefix = "HOST_"
+			case HostCross:
+				prefix = "HOST_CROSS_"
+			case Device:
+				prefix = "TARGET_"
 
-		}
+			}
 
-		config := ctx.Config().(Config)
-		if amod.Arch().ArchType != config.Targets[amod.Os().Class][0].Arch.ArchType {
-			prefix = "2ND_" + prefix
+			config := ctx.Config().(Config)
+			if amod.Arch().ArchType != config.Targets[amod.Os().Class][0].Arch.ArchType {
+				prefix = "2ND_" + prefix
+			}
 		}
 
 		return data.Custom(w, name, prefix, filepath.Dir(ctx.BlueprintFile(mod)))