diff --git a/main/src/main/scala/sbt/Main.scala b/main/src/main/scala/sbt/Main.scala
index 1aaa9333d..3499c9e28 100644
--- a/main/src/main/scala/sbt/Main.scala
+++ b/main/src/main/scala/sbt/Main.scala
@@ -221,7 +221,7 @@ object BuiltinCommands {
           Some(index.keyMap(key))
         catch {
           case NonFatal(ex) =>
-            s.log error ex.getMessage
+            s.log debug ex.getMessage
             None
         }
       }.collect { case Some(s) => s }.distinct