diff --git a/pyproject.toml b/pyproject.toml
index 96c43c2b..e0ec64af 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -69,15 +69,15 @@ keywords = [
 "Funding" = "https://owasp.org/donate/?reponame=www-project-cyclonedx&title=OWASP+CycloneDX"
 
 [tool.poetry.dependencies]
-python = "^3.9"
+python = ">=3.9, <4"
 packageurl-python = ">=0.11, <2"
-py-serializable =  "^2.1.0"
-sortedcontainers = "^2.4.0"
-license-expression = "^30"
-jsonschema = { version = "^4.25", extras=['format-nongpl'], optional=true }
+py-serializable =  ">=2.1.0, <3"
+sortedcontainers = ">=2.4.0, <3"
+license-expression = ">=30, <31"
+jsonschema = { version = ">=4.25, <5", extras=['format-nongpl'], optional=true }
 referencing = { version = ">=0.28.4", optional=true }  # in sync with the transitive dependency of `jsonschema`
 lxml = { version=">=4,<7", optional=true }
-typing_extensions = { version="^4.6", python = "<3.13"}  # for `@deprecated` - which was added in v4.5 but this version appesrs to be broken...
+typing_extensions = { version=">=4.6, <5", python = "<3.13"}  # for `@deprecated` - which was added in v4.5 but this version appesrs to be broken...
 
 [tool.poetry.extras]
 validation = ["jsonschema", "referencing", "lxml"]