diff --git a/queenbee/io/inputs/function.py b/queenbee/io/inputs/function.py
index 65b7f665..25856c86 100644
--- a/queenbee/io/inputs/function.py
+++ b/queenbee/io/inputs/function.py
@@ -5,7 +5,7 @@
 
 import os
 from typing import Union, List, Dict
-from pydantic import constr, Field
+from pydantic import constr, Field, validator
 from jsonschema import validate as json_schema_validator
 
 from .dag import DAGStringInput, DAGIntegerInput, DAGNumberInput, DAGBooleanInput, \
@@ -98,6 +98,12 @@ class FunctionFolderInput(DAGFolderInput):
         ' This path is relative to the working directory where the command is executed.'
     )
 
+    @validator('path')
+    def not_workspace_path(cls, v):
+        if v == '.':
+            raise ValueError('Input path for a function file cannot be "."')
+        return v
+
     @property
     def referenced_values(self) -> Dict[str, List[str]]:
         """Get referenced variables if any
diff --git a/tests/assets/functions/invalid/invalid_input_path.error b/tests/assets/functions/invalid/invalid_input_path.error
new file mode 100644
index 00000000..e211f36a
--- /dev/null
+++ b/tests/assets/functions/invalid/invalid_input_path.error
@@ -0,0 +1 @@
+Input path for a function file cannot be "."
\ No newline at end of file
diff --git a/tests/assets/functions/invalid/invalid_input_path.yaml b/tests/assets/functions/invalid/invalid_input_path.yaml
new file mode 100644
index 00000000..64ef5a66
--- /dev/null
+++ b/tests/assets/functions/invalid/invalid_input_path.yaml
@@ -0,0 +1,20 @@
+---
+type: Function
+name: split-grid-from-folder
+inputs:
+- type: FunctionFolderInput
+  annotations: {}
+  name: input-grid
+  description: Path to sensor grids folder.
+  default:
+  alias: []
+  required: true
+  spec:
+  path: "."
+outputs:
+- type: FunctionFolderOutput
+  name: output-folder
+  description: Output folder with new sensor grids.
+  path: "."
+  required: true
+command: honeybee-radiance grid split --folder . --log-file output/grids_info.json