diff --git a/core/shared/src/main/scala/coursier/core/Repository.scala b/core/shared/src/main/scala/coursier/core/Repository.scala
index 2d0f96dcf..297f95f9a 100644
--- a/core/shared/src/main/scala/coursier/core/Repository.scala
+++ b/core/shared/src/main/scala/coursier/core/Repository.scala
@@ -38,29 +38,6 @@ object Repository {
           )
             .withDefaultChecksums
       ))
-    def withJavadocSources: Artifact = {
-      val base = underlying.url.stripSuffix(".jar")
-      underlying.copy(extra = underlying.extra ++ Seq(
-        "sources" -> Artifact(
-          base + "-sources.jar",
-          Map.empty,
-          Map.empty,
-          Attributes("jar", "src"),  // Are these the right attributes?
-          changing = underlying.changing
-        )
-          .withDefaultChecksums
-          .withDefaultSignature,
-        "javadoc" -> Artifact(
-          base + "-javadoc.jar",
-          Map.empty,
-          Map.empty,
-          Attributes("jar", "javadoc"), // Same comment as above
-          changing = underlying.changing
-        )
-          .withDefaultChecksums
-          .withDefaultSignature
-      ))
-    }
   }
 }
 
diff --git a/core/shared/src/main/scala/coursier/maven/MavenSource.scala b/core/shared/src/main/scala/coursier/maven/MavenSource.scala
index 26973836d..06921e82d 100644
--- a/core/shared/src/main/scala/coursier/maven/MavenSource.scala
+++ b/core/shared/src/main/scala/coursier/maven/MavenSource.scala
@@ -11,6 +11,32 @@ case class MavenSource(
   import Repository._
   import MavenRepository._
 
+  private implicit class DocSourcesArtifactExtensions(val underlying: Artifact) {
+    def withJavadocSources: Artifact = {
+      val base = underlying.url.stripSuffix(".jar")
+      underlying.copy(extra = underlying.extra ++ Seq(
+        "sources" -> Artifact(
+          base + "-sources.jar",
+          Map.empty,
+          Map.empty,
+          Attributes("jar", "src"),  // Are these the right attributes?
+          changing = underlying.changing
+        )
+          .withDefaultChecksums
+          .withDefaultSignature,
+        "javadoc" -> Artifact(
+          base + "-javadoc.jar",
+          Map.empty,
+          Map.empty,
+          Attributes("jar", "javadoc"), // Same comment as above
+          changing = underlying.changing
+        )
+          .withDefaultChecksums
+          .withDefaultSignature
+      ))
+    }
+  }
+
   def artifacts(
     dependency: Dependency,
     project: Project