diff --git a/packages/ambertools/package.py b/packages/ambertools/package.py
index f680b43ce67b022f59b89111ee3b580d9802184f..abe7df7dd723e200dabeb83cb7218dad1ff6e393 100644
--- a/packages/ambertools/package.py
+++ b/packages/ambertools/package.py
@@ -19,6 +19,9 @@ class Ambertools(CMakePackage):
 
     maintainers("d-beltran")
 
+    # begin EBRAINS (added): add version
+    version("23_rc6", sha256="debb52e6ef2e1b4eaa917a8b4d4934bd2388659c660501a81ea044903bf9ee9d")
+    # end EBRAINS
     version("22jlmrcc", sha256="1571d4e0f7d45b2a71dce5999fa875aea8c90ee219eb218d7916bf30ea229121")
 
     depends_on("flex", type="build")
@@ -40,7 +43,10 @@ class Ambertools(CMakePackage):
         type=("build", "run"),
     )
     # Python dependencies
-    depends_on("python@3.8:3.10 +tkinter", type=("build", "run"))
+    # begin EBRAINS (modified): add version
+    depends_on("python@3.8:3.10 +tkinter", type=("build", "run"), when="@22jlmrcc")
+    depends_on("python@3.8: +tkinter", type=("build", "run"), when="@23_rc6")
+    # end EBRAINS
     depends_on("py-setuptools", type="build")
     depends_on("py-numpy", type=("build", "run"))
     depends_on("py-matplotlib", type=("build", "run"))