diff --git a/build.sbt b/build.sbt
index e5e4bc8c960f12a953a1e88ff51b1158909689f8..aa429a01bf5e94e0390013c7fa043c8bd31ed36d 100644
--- a/build.sbt
+++ b/build.sbt
@@ -37,6 +37,11 @@ val commonSettings3 = Seq(
 def withTests(project: Project): ClasspathDependency =
   project % "compile->compile;test->test"
 
+def githubProject(repo: String, commitHash: String) = RootProject(uri(s"$repo#$commitHash"))
+
+lazy val scallion = githubProject("https://github.com/epfl-lara/scallion.git", "08b333f9af2d8daa1fb7424cd47b0433cd5e9770")
+lazy val silex = githubProject("https://github.com/epfl-lara/silex.git", "eaf296425b9d8cc9100dfa66a079641ee4cfe4ae")
+
 lazy val root = Project(
   id = "lisa",
   base = file(".")
@@ -63,6 +68,8 @@ lazy val utils = Project(
 )
   .settings(commonSettings3)
   .dependsOn(kernel)
+  .dependsOn(silex)
+  .dependsOn(scallion % "compile->compile")
 
 lazy val theories = Project(
   id = "lisa-theories",