diff --git a/pkg/gen/filters/filterjava/filters.go b/pkg/gen/filters/filterjava/filters.go
index c6d66de8..9efcef77 100644
--- a/pkg/gen/filters/filterjava/filters.go
+++ b/pkg/gen/filters/filterjava/filters.go
@@ -2,8 +2,7 @@ package filterjava
 
 import "text/template"
 
-func PopulateFuncMap() template.FuncMap {
-	fm := make(template.FuncMap)
+func PopulateFuncMap(fm template.FuncMap) {
 	fm["javaDefault"] = javaDefault
 	fm["javaReturn"] = javaReturn
 	fm["javaParam"] = javaParam
@@ -12,5 +11,4 @@ func PopulateFuncMap() template.FuncMap {
 	fm["javaVars"] = javaVars
 	fm["javaType"] = javaType
 	fm["javaExtern"] = javaExtern
-	return fm
 }
diff --git a/pkg/gen/filters/funcmap.go b/pkg/gen/filters/funcmap.go
index 6c12f2ef..8a930668 100644
--- a/pkg/gen/filters/funcmap.go
+++ b/pkg/gen/filters/funcmap.go
@@ -6,6 +6,7 @@ import (
 	"github.com/apigear-io/cli/pkg/gen/filters/common"
 	"github.com/apigear-io/cli/pkg/gen/filters/filtercpp"
 	"github.com/apigear-io/cli/pkg/gen/filters/filtergo"
+	"github.com/apigear-io/cli/pkg/gen/filters/filterjava"
 	"github.com/apigear-io/cli/pkg/gen/filters/filterjs"
 	"github.com/apigear-io/cli/pkg/gen/filters/filterpy"
 	"github.com/apigear-io/cli/pkg/gen/filters/filterqt"
@@ -26,6 +27,7 @@ func PopulateFuncMap() template.FuncMap {
 	filterqt.PopulateFuncMap(fm)
 	filterjs.PopulateFuncMap(fm)
 	filterrs.PopulateFuncMap(fm)
+	filterjava.PopulateFuncMap(fm)
 
 	return fm
 }