diff --git a/README.md b/README.md
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--- a/README.md
+++ b/README.md
@@ -1,3 +1,14 @@
 # IPython Kernel for Jupyter
 
 This package provides the IPython kernel for Jupyter.
+
+## Installation from source
+
+1. `git clone`
+2. `cd ipykernel`
+3. `pip install --pre -e .`
+
+ 
+The `--pre` will only be needed while we haven't released IPython 4. Once that's done, it will never be needed again. `--pre` isn't needed if you already have IPython from master.
+
+After that, all normal `ipython` commands will use this newly-installed version of the kernel.