diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index f4232a8..399c437 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -16,7 +16,7 @@ jobs:
 
       - name: Install dependencies
         run: |
-          python3 -m pip install pytest lark-parser
+          python3 -m pip install -r requirements.in pytest
 
       - name: Run test suite
         run: |
diff --git a/README.md b/README.md
index 7f538d6..601772d 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # Step Physical File Validator
 
-Pure-python Step Physical File Validator and Parser implemented using Lark  (`pip install lark-parser`).
+Pure-python Step Physical File Validator and Parser implemented using Lark  (`pip install -r requirements.in`).
 
 ## Example command line usage:
 
@@ -34,4 +34,4 @@ Expecting HEADER
 
 $ python main.py fixtures\pass_1.ifc
 Valid
-~~~
\ No newline at end of file
+~~~
diff --git a/requirements.in b/requirements.in
new file mode 100644
index 0000000..0aa1d5a
--- /dev/null
+++ b/requirements.in
@@ -0,0 +1 @@
+lark-parser