diff --git a/README.md b/README.md
index 432e728a3cae2d779273648df78716792d9bbf86..a54fae77c391966a4db9215b6c5f56f7c168cdff 100644
--- a/README.md
+++ b/README.md
@@ -189,7 +189,7 @@ cp -r ./examples/concepts/* ./workspace/phen/concepts
 	From the command prompt, copy example phenotype configuration files `/examples/config.json` to the phenotype directory:
 
 ```bash
-cp -r ./examples/config1.yaml ./workspace/phen/config.yaml
+cp -r ./examples/config1.yml ./workspace/phen/config.yml
 ```
 
    - You can view the configuarion file here [`config.json`](./examples/config.json) 
diff --git a/docs/index.md b/docs/index.md
index 430dfb5dd038853e7420d3139c99f9b281693f2a..c4ec6e027020da1362b579b036f0ef12c5f6a551 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -71,13 +71,13 @@ workspace/                          # Default workspace directory
 │   │   ├── omop/                   # Processed phenotype concept sets in OMOP CDM database exported as CSV files
 │   ├── map/                        # Process mapping from source to target code types
 │   │   ├── errors/                 # Errors recorded during mapping process
-│   ├── config.yaml                 # Phenotype configuration file
-│   ├── vocab_versions.yaml         # Versions file for vocabularies used to generate concept sets
+│   ├── config.yml                 # Phenotype configuration file
+│   ├── vocab_versions.yml         # Versions file for vocabularies used to generate concept sets
 ``` 
 
 ### **Configuration File**
 
-Each phenotype is defined by configuration is stored in the root of the phenotype directory in `config.yaml`. The file is yaml format. 
+Each phenotype is defined by configuration is stored in the root of the phenotype directory in `config.yml`. The file is yaml format. 
 
 #### **Root Phenotype Element**  
 - `phenotype`: **(object)** The root element containing all phenotype-related concept sets and metadata.