diff --git a/genrule/genrule.go b/genrule/genrule.go
index 9839410..8c1969f 100644
--- a/genrule/genrule.go
+++ b/genrule/genrule.go
@@ -142,12 +142,6 @@
 }
 
 func (g *Module) GenerateAndroidBuildActions(ctx android.ModuleContext) {
-	toolFiles := ctx.ExpandSources(g.properties.Tool_files, nil)
-	if len(g.properties.Tools) == 0 && len(toolFiles) == 0 {
-		ctx.ModuleErrorf("at least one `tools` or `tool_files` is required")
-		return
-	}
-
 	if len(g.properties.Export_include_dirs) > 0 {
 		for _, dir := range g.properties.Export_include_dirs {
 			g.exportedIncludeDirs = append(g.exportedIncludeDirs,
@@ -210,6 +204,7 @@
 		return
 	}
 
+	toolFiles := ctx.ExpandSources(g.properties.Tool_files, nil)
 	for _, tool := range toolFiles {
 		g.deps = append(g.deps, tool)
 		if _, exists := tools[tool.Rel()]; !exists {
@@ -227,6 +222,10 @@
 	rawCommand, err := android.Expand(task.cmd, func(name string) (string, error) {
 		switch name {
 		case "location":
+			if len(g.properties.Tools) == 0 && len(toolFiles) == 0 {
+				return "", fmt.Errorf("at least one `tools` or `tool_files` is required if $(location) is used")
+			}
+
 			if len(g.properties.Tools) > 0 {
 				return tools[g.properties.Tools[0]].String(), nil
 			} else {
diff --git a/java/java.go b/java/java.go
index 3663253..c2b039e 100644
--- a/java/java.go
+++ b/java/java.go
@@ -1031,7 +1031,7 @@
 
 	isWrapperVariant bool
 
-	wrapperFile android.SourcePath
+	wrapperFile android.Path
 	binaryFile  android.OutputPath
 }
 
@@ -1048,7 +1048,13 @@
 		j.isWrapperVariant = true
 
 		if String(j.binaryProperties.Wrapper) != "" {
-			j.wrapperFile = android.PathForModuleSrc(ctx, String(j.binaryProperties.Wrapper)).SourcePath
+			wrapperSrcs := ctx.ExpandSources([]string{String(j.binaryProperties.Wrapper)}, nil)
+			if len(wrapperSrcs) == 1 {
+				j.wrapperFile = wrapperSrcs[0]
+			} else {
+				ctx.PropertyErrorf("wrapper", "module providing wrapper must produce exactly one file")
+				return
+			}
 		} else {
 			j.wrapperFile = android.PathForSource(ctx, "build/soong/scripts/jar-wrapper.sh")
 		}
@@ -1065,6 +1071,8 @@
 func (j *Binary) DepsMutator(ctx android.BottomUpMutatorContext) {
 	if ctx.Arch().ArchType == android.Common {
 		j.deps(ctx)
+	} else {
+		android.ExtractSourcesDeps(ctx, []string{String(j.binaryProperties.Wrapper)})
 	}
 }