diff --git a/.github/workflows/_matrix-and-codecov-on-merge-to-main.yml b/.github/workflows/_matrix-and-codecov-on-merge-to-main.yml
index 5b684a9..152838d 100644
--- a/.github/workflows/_matrix-and-codecov-on-merge-to-main.yml
+++ b/.github/workflows/_matrix-and-codecov-on-merge-to-main.yml
@@ -57,7 +57,9 @@ jobs:
       - name: Install ${{ inputs.project }} and requirements
         run: |
           conda install --file requirements/run.txt
-          conda install --file requirements/run-ext.txt
+          if [ -f requirements/run-ext.txt ]; then
+            conda install --file requirements/run-ext.txt
+          fi
           conda install --file requirements/test.txt
           if ${{ inputs.c_extension }}; then
             conda install --file requirements/build.txt
diff --git a/.github/workflows/_publish-docs-on-release.yml b/.github/workflows/_publish-docs-on-release.yml
index fc9b079..4bec4ad 100644
--- a/.github/workflows/_publish-docs-on-release.yml
+++ b/.github/workflows/_publish-docs-on-release.yml
@@ -41,7 +41,9 @@ jobs:
       - name: IInstall ${{ inputs.project }} and docs requirements
         run: |
           conda install --file requirements/run.txt
-          conda install --file requirements/run-ext.txt
+          if [ -f requirements/run-ext.txt ]; then
+            conda install --file requirements/run-ext.txt
+          fi
           conda install --file requirements/docs.txt
           if ${{ inputs.c_extension }}; then
             conda install --file requirements/build.txt
diff --git a/.github/workflows/_tests-on-pr.yml b/.github/workflows/_tests-on-pr.yml
index 57615f5..83e2571 100644
--- a/.github/workflows/_tests-on-pr.yml
+++ b/.github/workflows/_tests-on-pr.yml
@@ -46,7 +46,9 @@ jobs:
       - name: Install ${{ inputs.project }} and requirements
         run: |
           conda install --file requirements/run.txt
-          conda install --file requirements/run-ext.txt
+          if [ -f requirements/run-ext.txt ]; then
+            conda install --file requirements/run-ext.txt
+          fi
           conda install --file requirements/test.txt
           if ${{ inputs.c_extension }}; then
             conda install --file requirements/build.txt