diff --git a/core/src/main/scala/sbt/internal/librarymanagement/LMSysProp.scala b/core/src/main/scala/sbt/internal/librarymanagement/LMSysProp.scala
index 1fe46916f..15bb4a9e5 100644
--- a/core/src/main/scala/sbt/internal/librarymanagement/LMSysProp.scala
+++ b/core/src/main/scala/sbt/internal/librarymanagement/LMSysProp.scala
@@ -54,5 +54,5 @@ object LMSysProp {
     }
   }
 
-  lazy val useGigahorse: Boolean = getOrTrue("sbt.gigahorse")
+  lazy val useGigahorse: Boolean = getOrFalse("sbt.gigahorse")
 }