diff --git a/README.md b/README.md
index 5f21316..d0d9993 100644
--- a/README.md
+++ b/README.md
@@ -15,9 +15,9 @@ The box plots and jitter plots I have in mind apply to the case where one axis i
 
 ## Installation
 
-You can install altair-catplot using pip.
+You can install altair-catplot using pip. You will need to have a recent version of Altair and all of its dependencies installed.
 
-    pip install altair-catplot
+    pip install altair_catplot
 
 ## Usage
 
diff --git a/notebooks/readme_notebook.ipynb b/notebooks/readme_notebook.ipynb
index ec9bf66..249f9bb 100644
--- a/notebooks/readme_notebook.ipynb
+++ b/notebooks/readme_notebook.ipynb
@@ -30,9 +30,9 @@
    "source": [
     "## Installation\n",
     "\n",
-    "You can install altair-catplot using pip.\n",
+    "You can install altair-catplot using pip. You will need to have a recent version of Altair and all of its dependencies installed.\n",
     "\n",
-    "    pip install altair-catplot"
+    "    pip install altair_catplot"
    ]
   },
   {