diff --git a/repo/pyproject.toml b/repo/pyproject.toml
index a876dc3..c24baaa 100644
--- a/repo/pyproject.toml
+++ b/repo/pyproject.toml
@@ -10,7 +10,7 @@ license-files = [ "LICENSE" ]
 readme = "README.md"
 dependencies = [
   "securesystemslib[awskms, azurekms, gcpkms, sigstore] ~= 1.2",
-  "tuf ~= 5.1",
+  "tuf >= 5.1,< 7.0",
   "click ~= 8.1",
 ]
 requires-python = ">=3.10"
diff --git a/signer/pyproject.toml b/signer/pyproject.toml
index 0611494..bb82f8b 100644
--- a/signer/pyproject.toml
+++ b/signer/pyproject.toml
@@ -12,7 +12,7 @@ dependencies = [
   "packaging ~= 24.0",
   "platformdirs ~= 4.2",
   "securesystemslib[awskms,azurekms,gcpkms,hsm,sigstore] ~= 1.2",
-  "tuf ~= 5.1",
+  "tuf >= 5.1,< 7.0",
   "click ~= 8.1",
 ]
 requires-python = ">=3.9"