diff --git a/.github/workflows/conda-package.yml b/.github/workflows/conda-package.yml
index 8a738e4..69f0dc1 100644
--- a/.github/workflows/conda-package.yml
+++ b/.github/workflows/conda-package.yml
@@ -1,5 +1,8 @@
 name: Conda package
 
+# Declare default permissions as read only.
+permissions: read-all
+
 on:
   push:
     branches:
diff --git a/.github/workflows/pre-commit.yml b/.github/workflows/pre-commit.yml
index 1c6bf61..965c76b 100644
--- a/.github/workflows/pre-commit.yml
+++ b/.github/workflows/pre-commit.yml
@@ -1,5 +1,8 @@
 name: pre-commit
 
+# Declare default permissions as read only.
+permissions: read-all
+
 on:
   pull_request:
   push: