diff --git a/requirements.txt b/requirements.txt
index b2a0df8d10..1eee1701a8 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -13,12 +13,12 @@ pytest
 python-constraint
 pyyaml
 scipy
-simplejson
-svgwrite
-termcolor
-textx
-tinyfpgab
-tinyprog
+simplejson==3.17.6
+svgwrite==1.4.1
+termcolor==1.1.0
+textx==3.0.0
+tinyfpgab==1.1.0
+tinyprog==1.0.21
 yapf==0.26.0
 https://github.com/chipsalliance/f4pga/archive/main.zip#subdirectory=f4pga
 fasm