diff --git a/project/SphinxDoc.scala b/project/SphinxDoc.scala
index 4bdb59e3da..deea7d2479 100644
--- a/project/SphinxDoc.scala
+++ b/project/SphinxDoc.scala
@@ -19,6 +19,9 @@ object SphinxDoc {
 
   def docsSettings = Seq(
     sourceDirectory in Sphinx <<= baseDirectory / "rst",
+    watchSources <++= (sourceDirectory in Sphinx, excludeFilter in Global) map { (source, excl) =>
+      source descendantsExcept ("*.rst", excl) get
+    },
     sphinxPackages in Sphinx <+= baseDirectory { _ / "_sphinx" / "pygments" },
     // copy akka-contrib/docs into our rst_preprocess/contrib (and apply substitutions)
     preprocess in Sphinx <<= (preprocess in Sphinx,