diff --git a/setup.cfg b/setup.cfg
index 053cc5ab..0be74683 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -15,8 +15,8 @@ packages = find:
 python_requires = >=3.9
 setup_requires = setuptools_scm
 install_requires =
-    bitstring
-    hissw
+    bitstring~=4.2
+    hissw~=2.3
     intervaltree
     numpy
     matplotlib
@@ -24,11 +24,11 @@ install_requires =
     polling2
     python-dateutil
     pyyaml
-    roentgen
+    roentgen~=2.1
     scp
-    spiceypy
-    sunpy>=4.0.1
-    watchdog==6.0.0
+    spiceypy~=6.0
+    sunpy~=5.1
+    watchdog~=6.0
     stixdcpy==3.0