diff --git a/dev/env-py38.yaml b/dev/env-py38.yaml
index ade6b2b4..28fb23e2 100644
--- a/dev/env-py38.yaml
+++ b/dev/env-py38.yaml
@@ -4,7 +4,7 @@ channels:
   - conda-forge
   - defaults
 dependencies:
-  - bioimageio.spec>=0.5.2post1
+  - bioimageio.spec>-0.5.2.post1
   - black
   - crick # uncommented
   - filelock
diff --git a/dev/env-tf.yaml b/dev/env-tf.yaml
index 06451185..1ec93a5c 100644
--- a/dev/env-tf.yaml
+++ b/dev/env-tf.yaml
@@ -4,7 +4,7 @@ channels:
   - conda-forge
   - defaults
 dependencies:
-  - bioimageio.spec>=0.5.2post1
+  - bioimageio.spec>-0.5.2.post1
   - black
   # - crick  # currently requires python<=3.9
   - filelock
diff --git a/dev/env-wo-python.yaml b/dev/env-wo-python.yaml
index 86dad127..93f36923 100644
--- a/dev/env-wo-python.yaml
+++ b/dev/env-wo-python.yaml
@@ -4,7 +4,7 @@ channels:
   - conda-forge
   - defaults
 dependencies:
-  - bioimageio.spec>=0.5.2
+  - bioimageio.spec>-0.5.2.post1
   - black
   # - crick  # currently requires python<=3.9
   - filelock
diff --git a/dev/env.yaml b/dev/env.yaml
index e0634abe..19ae11cf 100644
--- a/dev/env.yaml
+++ b/dev/env.yaml
@@ -3,7 +3,7 @@ channels:
   - conda-forge
   - defaults
 dependencies:
-  - bioimageio.spec>=0.5.2post1
+  - bioimageio.spec>-0.5.2.post1
   - black
   # - crick  # currently requires python<=3.9
   - filelock