diff --git a/conf/environment-symbiflow.yml b/conf/environment-symbiflow.yml
index ca2f3b706..f5856e70d 100644
--- a/conf/environment-symbiflow.yml
+++ b/conf/environment-symbiflow.yml
@@ -13,7 +13,8 @@ dependencies:
   - litex-hub::nextpnr-ecp5
   - litex-hub::nextpnr-ice40
 # Temporarily pin Yosys until symbiflow-yosys-plugins catches up
-  - litex-hub::yosys=0.33_11_g31ee566ec=20230724_080446_py37
+#   AND https://github.com/YosysHQ/yosys/issues/4081 is resolved
+  - litex-hub::yosys=0.29_35_g57c9eb70f=20230524_010725_py37
   - litex-hub::iceprog
   - litex-hub::prjxray-tools
   - litex-hub::prjxray-db
diff --git a/conf/environment.yml b/conf/environment.yml
index b725ed6a6..2da5dfc91 100644
--- a/conf/environment.yml
+++ b/conf/environment.yml
@@ -13,7 +13,8 @@ dependencies:
   - litex-hub::nextpnr-ice40
   - litex-hub::iceprog
 # Temporarily pin Yosys until symbiflow-yosys-plugins catches up
-  - litex-hub::yosys=0.33_11_g31ee566ec=20230724_080446_py37
+#   AND https://github.com/YosysHQ/yosys/issues/4081 is resolved
+  - litex-hub::yosys=0.29_35_g57c9eb70f=20230524_010725_py37
   - litex-hub::symbiflow-yosys-plugins
   - libevent
   - json-c