diff --git a/test/index.spec.js b/test/index.spec.js
index fde02f4ff9f6098fb4ea85d0d8d8e538ad4bf8fe_dGVzdC9pbmRleC5zcGVjLmpz..2396ed31cd3eea69b8b979b4e2378cb176701b57_dGVzdC9pbmRleC5zcGVjLmpz 100644
--- a/test/index.spec.js
+++ b/test/index.spec.js
@@ -117,6 +117,10 @@
 }
 
 describe('config.io', () => {
+  beforeEach(() => {
+    process.env.NODE_ENV = 'test'
+  })
+
   if (semver.satisfies(process.version, '>=13.2.0')) {
     setupAllTestsWith('ESM')
   }
diff --git a/test/load/options/8-map-filenames-tpl/1-single-env.spec.yaml b/test/load/options/8-map-filenames-tpl/1-single-env.spec.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..2396ed31cd3eea69b8b979b4e2378cb176701b57_dGVzdC9sb2FkL29wdGlvbnMvOC1tYXAtZmlsZW5hbWVzLXRwbC8xLXNpbmdsZS1lbnYuc3BlYy55YW1s
--- /dev/null
+++ b/test/load/options/8-map-filenames-tpl/1-single-env.spec.yaml
@@ -0,0 +1,6 @@
+it: should load the correct file using mapFilenamesTpl
+start:
+  simpleMode: true
+  mapFilenamesTpl: ns__<%=ns%>_env__<%=env%>
+res:
+  super: val
diff --git a/test/load/options/8-map-filenames-tpl/2-multiple-env.spec.yaml b/test/load/options/8-map-filenames-tpl/2-multiple-env.spec.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..2396ed31cd3eea69b8b979b4e2378cb176701b57_dGVzdC9sb2FkL29wdGlvbnMvOC1tYXAtZmlsZW5hbWVzLXRwbC8yLW11bHRpcGxlLWVudi5zcGVjLnlhbWw=
--- /dev/null
+++ b/test/load/options/8-map-filenames-tpl/2-multiple-env.spec.yaml
@@ -0,0 +1,8 @@
+it: should load properly multiple environments using mapFilenamesTpl
+start:
+  autoload:
+  - base
+  mapFilenamesTpl: ns__<%=ns%>_env__<%=env%>
+res:
+  base:
+    super: other val
diff --git a/test/load/options/8-map-filenames-tpl/ns___env__default.yaml b/test/load/options/8-map-filenames-tpl/ns___env__default.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..2396ed31cd3eea69b8b979b4e2378cb176701b57_dGVzdC9sb2FkL29wdGlvbnMvOC1tYXAtZmlsZW5hbWVzLXRwbC9uc19fX2Vudl9fZGVmYXVsdC55YW1s
--- /dev/null
+++ b/test/load/options/8-map-filenames-tpl/ns___env__default.yaml
@@ -0,0 +1,1 @@
+super: val
diff --git a/test/load/options/8-map-filenames-tpl/ns__base_env__default.yaml b/test/load/options/8-map-filenames-tpl/ns__base_env__default.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..2396ed31cd3eea69b8b979b4e2378cb176701b57_dGVzdC9sb2FkL29wdGlvbnMvOC1tYXAtZmlsZW5hbWVzLXRwbC9uc19fYmFzZV9lbnZfX2RlZmF1bHQueWFtbA==
--- /dev/null
+++ b/test/load/options/8-map-filenames-tpl/ns__base_env__default.yaml
@@ -0,0 +1,1 @@
+super: val
diff --git a/test/load/options/8-map-filenames-tpl/ns__base_env__test.yaml b/test/load/options/8-map-filenames-tpl/ns__base_env__test.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..2396ed31cd3eea69b8b979b4e2378cb176701b57_dGVzdC9sb2FkL29wdGlvbnMvOC1tYXAtZmlsZW5hbWVzLXRwbC9uc19fYmFzZV9lbnZfX3Rlc3QueWFtbA==
--- /dev/null
+++ b/test/load/options/8-map-filenames-tpl/ns__base_env__test.yaml
@@ -0,0 +1,1 @@
+super: other val