diff --git a/docs/changelog/2695.doc.rst b/docs/changelog/2695.doc.rst
new file mode 100644
index 000000000..3f0b3f1e1
--- /dev/null
+++ b/docs/changelog/2695.doc.rst
@@ -0,0 +1 @@
+Add breaking-change documentation for empty ``install_command`` values - by :user:`jayaddison`.
diff --git a/docs/faq.rst b/docs/faq.rst
index 506c595a6..b4ae18791 100644
--- a/docs/faq.rst
+++ b/docs/faq.rst
@@ -48,6 +48,9 @@ tox 4 - changed INI rules
   this worked in tox 3, it was never supported officially. Additionally, in the context of a new virtual environment
   this flag makes no sense anyway.
 
+- tox 4 requires the ``install_command`` to evaluate to a non-empty value for each target environment.  In tox 3, an
+  empty value would be substituted for the default install command.
+
 tox 4 - known regressions
 +++++++++++++++++++++++++