diff --git a/.github/workflows/python-app.yaml b/.github/workflows/python-app.yaml
index 4abda529..ba859983 100644
--- a/.github/workflows/python-app.yaml
+++ b/.github/workflows/python-app.yaml
@@ -17,8 +17,8 @@ jobs:
 
 
     steps:
-    - name: Install libfabric
-      run: sudo apt-get update && sudo apt-get install -y libfabric-bin
+    - name: Install system dependencies
+      run: sudo apt-get update && sudo apt-get install -y libfabric-bin libhdf5-dev pkg-config
       
     - uses: actions/checkout@v2
     - name: Set up Python 3
diff --git a/mtuq/greens_tensor/CPS.py b/mtuq/greens_tensor/CPS.py
index f2f5cb1f..6d525cca 100644
--- a/mtuq/greens_tensor/CPS.py
+++ b/mtuq/greens_tensor/CPS.py
@@ -7,7 +7,7 @@
 
 class GreensTensor(GreensTensorBase):
     """
-    FK Green's tensor object
+    CPS Green's tensor object
 
     Overloads base class with machinery for working with CPS-style
     Green's functions
@@ -19,7 +19,7 @@ def __init__(self, *args, **kwargs):
         if 'type:greens' not in self.tags:
             self.tags += ['type:greens']
 
-        if 'type:velocity' not in self.tags:
+        if 'type:velocity' not in self.tags or 'type:displacement' not in self.tags:
             self.tags += ['type:velocity']
 
         if 'units:m' not in self.tags:
diff --git a/mtuq/greens_tensor/FK.py b/mtuq/greens_tensor/FK.py
index dfa041e7..d647f4f3 100644
--- a/mtuq/greens_tensor/FK.py
+++ b/mtuq/greens_tensor/FK.py
@@ -29,7 +29,7 @@ def __init__(self, *args, **kwargs):
         if 'type:greens' not in self.tags:
             self.tags += ['type:greens']
 
-        if 'type:velocity' not in self.tags:
+        if 'type:velocity' not in self.tags or 'type:displacement' not in self.tags:
             self.tags += ['type:velocity']
 
         if 'units:m' not in self.tags: