diff --git a/packages/hxtorch/package.py b/packages/hxtorch/package.py
index 2b2383ad8444961570b06680a15924374107ef9d..c84905874a58e6f874ccae12fbc84769a94e147b 100644
--- a/packages/hxtorch/package.py
+++ b/packages/hxtorch/package.py
@@ -14,10 +14,10 @@ class Hxtorch(WafPackage):
     # This repo provides a waf binary used for the build below
     git      = "https://github.com/electronicvisions/pynn-brainscales.git"
 
-    version('6.0-a1', branch='waf')
+    version('6.0-rc1', branch='waf')
 
     # PPU compiler dependencies
-    depends_on('oppulance@6.0-a1')
+    depends_on('oppulance@6.0-rc1')
 
     # host software dependencies
     depends_on('bitsery', type=('build', 'link', 'run'))
diff --git a/packages/oppulance/package.py b/packages/oppulance/package.py
index cc82f3b6028cf9ad4f734f393a3afba84a6b7bbb..9a6168af0edd94c6fec4c23bdf0e9cf02882f66f 100644
--- a/packages/oppulance/package.py
+++ b/packages/oppulance/package.py
@@ -22,8 +22,8 @@ class Oppulance(Package):
 
     releases = [
         {
-            'version': '6.0-a1',
-            'tag': 'ebrains-6.0-a1'
+            'version': '6.0-rc1',
+            'tag': 'ebrains-6.0-rc1'
         },
     ]
 
diff --git a/packages/pynn-brainscales/package.py b/packages/pynn-brainscales/package.py
index 8557135e70673c529de185bf48fb8485a406b534..a5290d9e83aa8041a69d779b2c21488a23e8175b 100644
--- a/packages/pynn-brainscales/package.py
+++ b/packages/pynn-brainscales/package.py
@@ -13,10 +13,10 @@ class PynnBrainscales(WafPackage):
     homepage = "https://github.com/electronicvisions/pynn-brainscales"
     git      = "https://github.com/electronicvisions/pynn-brainscales.git"
 
-    version('6.0-a1', branch='waf')
+    version('6.0-rc1', branch='waf')
 
     # PPU compiler dependencies
-    depends_on('oppulance@6.0-a1')
+    depends_on('oppulance@6.0-rc1')
 
     # host software dependencies
     depends_on('bitsery', type=('build', 'link', 'run'))
diff --git a/spack.yaml b/spack.yaml
index 647a458b878431fe95609b1cb27f2627d811c6dc..1a29f7fb40fea94d87eacdbee78c837740d167ef 100644
--- a/spack.yaml
+++ b/spack.yaml
@@ -21,7 +21,7 @@ spack:
     - biobb-model@4.0.0
     - biobb-structure-checking@3.12.1
     - biobb-structure-utils@4.0.0
-    - hxtorch@6.0-a1
+    - hxtorch@6.0-rc1
     - nest@3.5 +sonata
     - neuron@8.2.2 +mpi
     - nglview@3.0.4
@@ -67,7 +67,7 @@ spack:
     - py-tvb-library@2.8.1
     - py-tvb-storage@2.8.1
     - py-viziphant@0.3.0
-    - pynn-brainscales@6.0-a1
+    - pynn-brainscales@6.0-rc1
     - r-rgsl@0.1
     - r-sbtabvfgen@0.1
     - r-uqsa@2.2