diff --git a/.github/scripts/check-cross-version-deps.sc b/.github/scripts/check-cross-version-deps.sc
new file mode 100755
index 0000000000..07e0defd87
--- /dev/null
+++ b/.github/scripts/check-cross-version-deps.sc
@@ -0,0 +1,57 @@
+#!/usr/bin/env -S scala-cli shebang
+//> using scala 3
+//> using toolkit default
+
+val modules =
+  os.proc(os.pwd / "mill", "-i", "resolve", "__[]")
+    .call(cwd = os.pwd)
+    .out
+    .lines()
+
+for { module <- modules } {
+  println(s"Checking for $module...")
+  val depRegex            = "[│└─\\S\\s]+\\s([\\w.-]+):([\\w.-]+):([\\w\\s\\S.-]+)".r
+  val scalaDepSuffixRegex = "^(.+?)(_[23](?:\\.\\d{2})?)?$".r
+  val deps = os.proc(os.pwd / "mill", "-i", s"$module.ivyDepsTree")
+    .call(cwd = os.pwd)
+    .out
+    .lines()
+    .map { case depRegex(org, name, depVersion) => (org, name, depVersion) }
+  val scalaVersionsByOrgAndName = deps
+    .groupBy { case (org, scalaDepSuffixRegex(nameWithoutSuffix, _), _) =>
+      s"$org:$nameWithoutSuffix"
+    }
+    .map { case (key, entries) =>
+      key -> entries.map { case (_, scalaDepSuffixRegex(_, scalaVersion), _) =>
+        scalaVersion
+      }.distinct
+    }
+    .filter { case (_, scalaVersions) => scalaVersions.head != null } // filter out non-Scala deps
+  println("Checking for clashing dependency Scala versions...")
+  val conflictEntries: Map[String, Vector[String]] =
+    scalaVersionsByOrgAndName
+      .filter { case (key, scalaVersions) =>
+        if scalaVersions.length == 1 then
+          println(s"[info] $key${scalaVersions.head} (OK)")
+          false
+        else
+          println(
+            s"[${Console.RED}error${Console.RESET}] $key: multiple conflicting Scala versions: ${scalaVersions.mkString(", ")}"
+          )
+          true
+      }
+  if conflictEntries.nonEmpty then
+    println(s"${Console.RED}ERROR: Found ${conflictEntries.size} conflicting entries for $module:")
+    conflictEntries.foreach {
+      case (key, scalaVersions) =>
+        println(s"  $key: multiple conflicting Scala versions: ${scalaVersions.mkString(", ")}")
+    }
+    println(Console.RESET)
+    sys.exit(1)
+  else println(s"[info] $module OK")
+}
+
+println("Checks completed for:")
+modules.foreach(m => println(s"  $m"))
+println("No conflicts detected.")
+sys.exit(0)
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index daf53a9ab9..17f799c3a3 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -1493,6 +1493,8 @@ jobs:
       run: ./mill -i __.checkNativeImageConfFormat
     - name: Check Ammonite availability
       run: ./mill -i 'dummy.amm[_].resolvedRunIvyDeps'
+    - name: Check for cross Scala version conflicts
+      run: .github/scripts/check-cross-version-deps.sc
     - name: Scalafix check
       run: |
         ./mill -i __.fix --check || (
diff --git a/project/deps.sc b/project/deps.sc
index 949222345f..d2a02e7102 100644
--- a/project/deps.sc
+++ b/project/deps.sc
@@ -160,6 +160,7 @@ object Deps {
   def coursierCli = ivy"io.get-coursier:coursier-cli_2.13:${Versions.coursierCli}"
   def coursierJvm = ivy"io.get-coursier:coursier-jvm_2.13:${Versions.coursier}"
     .exclude(("com.github.plokhotnyuk.jsoniter-scala", "jsoniter-scala-core_2.13"))
+    .exclude("io.get-coursier" -> "dependency_2.13")
   def coursierLauncher = ivy"io.get-coursier:coursier-launcher_2.13:${Versions.coursier}"
     .exclude(("ai.kien", "python-native-libs_2.13"))
     .exclude(("org.scala-lang.modules", "scala-collection-compat_2.13"))