diff --git a/modules.go b/modules.go
index 9337d4d..8a2d580 100644
--- a/modules.go
+++ b/modules.go
@@ -2115,6 +2115,7 @@ func (e *Executor) moduleIncludeVars(args map[string]any) (*TaskResult, error) {
 	dir := getStringArg(args, "dir", "")
 	name := getStringArg(args, "name", "")
 	filesMatching := getStringArg(args, "files_matching", "")
+	extensions := normalizeIncludeVarsExtensions(normalizeStringList(args["extensions"]))
 	hashBehaviour := lower(getStringArg(args, "hash_behaviour", "replace"))
 	depth := getIntArg(args, "depth", 0)
 
@@ -2149,7 +2150,7 @@ func (e *Executor) moduleIncludeVars(args map[string]any) (*TaskResult, error) {
 
 	if dir != "" {
 		dir = e.resolveLocalPath(dir)
-		files, err := collectIncludeVarsFiles(dir, depth, filesMatching)
+		files, err := collectIncludeVarsFiles(dir, depth, filesMatching, extensions)
 		if err != nil {
 			return nil, err
 		}
@@ -2176,7 +2177,31 @@ func (e *Executor) moduleIncludeVars(args map[string]any) (*TaskResult, error) {
 	return &TaskResult{Changed: true, Msg: msg}, nil
 }
 
-func collectIncludeVarsFiles(dir string, depth int, filesMatching string) ([]string, error) {
+func normalizeIncludeVarsExtensions(values []string) []string {
+	if len(values) == 0 {
+		return []string{".json", ".yml", ".yaml"}
+	}
+
+	extensions := make([]string, 0, len(values))
+	seen := make(map[string]bool, len(values))
+	for _, value := range values {
+		ext := lower(corexTrimSpace(value))
+		if ext == "" {
+			continue
+		}
+		if !corexHasPrefix(ext, ".") {
+			ext = "." + ext
+		}
+		if seen[ext] {
+			continue
+		}
+		seen[ext] = true
+		extensions = append(extensions, ext)
+	}
+	return extensions
+}
+
+func collectIncludeVarsFiles(dir string, depth int, filesMatching string, extensions []string) ([]string, error) {
 	info, err := os.Stat(dir)
 	if err != nil {
 		return nil, coreerr.E("Executor.moduleIncludeVars", "read vars dir", err)
@@ -2199,6 +2224,10 @@ func collectIncludeVarsFiles(dir string, depth int, filesMatching string) ([]str
 	}
 
 	var files []string
+	allowed := make(map[string]bool, len(extensions))
+	for _, ext := range extensions {
+		allowed[ext] = true
+	}
 	stack := []dirEntry{{path: dir, depth: 0}}
 	for len(stack) > 0 {
 		current := stack[len(stack)-1]
@@ -2221,12 +2250,13 @@ func collectIncludeVarsFiles(dir string, depth int, filesMatching string) ([]str
 			}
 
 			ext := lower(filepath.Ext(entry.Name()))
-			if ext == ".yml" || ext == ".yaml" {
-				if matcher != nil && !matcher.MatchString(entry.Name()) {
-					continue
-				}
-				files = append(files, fullPath)
+			if !allowed[ext] {
+				continue
 			}
+			if matcher != nil && !matcher.MatchString(entry.Name()) {
+				continue
+			}
+			files = append(files, fullPath)
 		}
 	}
 
diff --git a/modules_adv_test.go b/modules_adv_test.go
index bea3b3a..d27e5e6 100644
--- a/modules_adv_test.go
+++ b/modules_adv_test.go
@@ -908,6 +908,45 @@ func TestModulesAdv_ModuleIncludeVars_Good_LoadSingleFile(t *testing.T) {
 	assert.Equal(t, true, nested["enabled"])
 }
 
+func TestModulesAdv_ModuleIncludeVars_Good_LoadJSONFileByDefault(t *testing.T) {
+	dir := t.TempDir()
+	varsPath := joinPath(dir, "vars.json")
+	require.NoError(t, writeTestFile(varsPath, []byte(`{"app_name":"demo","app_port":8080}`), 0644))
+
+	e := NewExecutor("/tmp")
+
+	result, err := e.moduleIncludeVars(map[string]any{
+		"file": varsPath,
+	})
+
+	require.NoError(t, err)
+	assert.True(t, result.Changed)
+	assert.False(t, result.Failed)
+	assert.Equal(t, "demo", e.vars["app_name"])
+	assert.Equal(t, 8080, e.vars["app_port"])
+}
+
+func TestModulesAdv_ModuleIncludeVars_Good_CustomExtensionsFilter(t *testing.T) {
+	dir := t.TempDir()
+	require.NoError(t, writeTestFile(joinPath(dir, "01-ignored.yml"), []byte("ignored_value: false\n"), 0644))
+	require.NoError(t, writeTestFile(joinPath(dir, "02-selected.vars"), []byte("selected_value: included\n"), 0644))
+
+	e := NewExecutor("/tmp")
+
+	result, err := e.moduleIncludeVars(map[string]any{
+		"dir":        dir,
+		"extensions": []any{"vars"},
+	})
+
+	require.NoError(t, err)
+	assert.True(t, result.Changed)
+	assert.Equal(t, "included", e.vars["selected_value"])
+	_, hasIgnored := e.vars["ignored_value"]
+	assert.False(t, hasIgnored)
+	assert.Contains(t, result.Msg, joinPath(dir, "02-selected.vars"))
+	assert.NotContains(t, result.Msg, joinPath(dir, "01-ignored.yml"))
+}
+
 func TestModulesAdv_ModuleIncludeVars_Good_LoadDirectoryWithMerge(t *testing.T) {
 	dir := t.TempDir()
 	require.NoError(t, writeTestFile(joinPath(dir, "01-base.yml"), []byte("app_name: demo\nnested:\n  a: 1\n"), 0644))