diff --git a/project/Mima.scala b/project/Mima.scala
index 98cfe9ed..ee900057 100644
--- a/project/Mima.scala
+++ b/project/Mima.scala
@@ -9,12 +9,13 @@ import scala.sys.process._
 object Mima {
 
   def binaryCompatibilityVersions: Set[String] =
-    Seq("git", "tag", "--merged", "HEAD^", "--contains", "15cf6005e")
+    Seq("git", "tag", "--merged", "HEAD^", "--contains", "1b90b2ac934eb41d6a82d10bd78561fa91fb4ead")
       .!!
       .linesIterator
       .map(_.trim)
       .filter(_.startsWith("v"))
       .map(_.stripPrefix("v"))
+      .filter(_ != "2.1.0-M5")
       .toSet
 
   def settings = Def.settings(