diff --git a/modules/lm-coursier/src/main/scala/coursier/lmcoursier/ToSbt.scala b/modules/lm-coursier/src/main/scala/coursier/lmcoursier/ToSbt.scala
index 258dd163b..53143405e 100644
--- a/modules/lm-coursier/src/main/scala/coursier/lmcoursier/ToSbt.scala
+++ b/modules/lm-coursier/src/main/scala/coursier/lmcoursier/ToSbt.scala
@@ -218,7 +218,11 @@ object ToSbt {
 
     val configReports = configs.map {
       case (config, extends0) =>
-        val configDeps = extends0.toSeq.sortBy(_.value).flatMap(configDependencies.getOrElse(_, Nil))
+        val configDeps = extends0
+          .toSeq
+          .sortBy(_.value)
+          .flatMap(configDependencies.getOrElse(_, Nil))
+          .distinct
         val subRes = resolutions(config).subset(configDeps)
 
         val reports = ToSbt.moduleReports(