diff --git a/Makefile b/Makefile
index 64f41de..04fda1b 100644
--- a/Makefile
+++ b/Makefile
@@ -14,5 +14,5 @@ test:
 	poetry run python -m pytest tests
 
 integration:
-	specdown run README.md --add-path ${PWD}/tests/scripts --env REPOSITORY_MODE=file --env CO2_SIGNAL_API_KEY=$(shell cat .co2_api_key)
+	specdown run README.md --add-path ${PWD}/tests/scripts --env DATA_SOURCE=file --env CO2_SIGNAL_API_KEY=$(shell cat .co2_api_key)
 
diff --git a/README.md b/README.md
index 8cf7b0e..5b70321 100644
--- a/README.md
+++ b/README.md
@@ -26,7 +26,7 @@ poetry run carbon_guard --help
 │    --data-source                [file|national-grid-e  Where to read carbon  │
 │                                 so-carbon-intensity|c  intensity data from   │
 │                                 o2-signal]             [env var:             │
-│                                                        REPOSITORY_MODE]      │
+│                                                        DATA_SOURCE]          │
 │                                                        [default:             │
 │                                                        national-grid-eso-ca… │
 │    --from-file-carbon-i…        PATH                   File to read carbon   │