diff --git a/medcat/utils/envsnapshot.py b/medcat/utils/envsnapshot.py
index f3418f5..c345ad5 100644
--- a/medcat/utils/envsnapshot.py
+++ b/medcat/utils/envsnapshot.py
@@ -1,4 +1,3 @@
-import pkg_resources
 import platform
 import logging
 import importlib.metadata
@@ -37,30 +36,6 @@ def get_direct_dependencies(include_extras: bool) -> list[str]:
     return reqs
 
 
-def _update_installed_dependencies_recursive(
-        gathered: dict[str, str],
-        package: pkg_resources.Distribution) -> dict[str, str]:
-    if package.project_name.lower() in gathered:
-        logger.debug("Trying to update already found transitive dependency "
-                     "'%'", package.egg_name)
-        return gathered
-    for req in package.requires():
-        if req.project_name.lower() in gathered:
-            logger.debug("Trying to look up already found transitive "
-                         "dependency '%'", req.project_name)
-            continue  # don't look for it again
-        try:
-            dep = pkg_resources.get_distribution(req.project_name)
-        except pkg_resources.DistributionNotFound as e:
-            logger.warning("Unable to locate requirement '%s':",
-                           req.project_name, exc_info=e)
-            continue
-        _update_installed_dependencies_recursive(gathered, dep)
-        # do this after so its dependencies get explored
-        gathered[dep.project_name.lower()] = dep.version
-    return gathered
-
-
 def get_transitive_deps(direct_deps: list[str]) -> dict[str, str]:
     """Get the transitive dependencies of the direct dependencies.
 
@@ -70,12 +45,45 @@ def get_transitive_deps(direct_deps: list[str]) -> dict[str, str]:
     Returns:
         dict[str, str]: The dependency names and their corresponding versions.
     """
-    # map from name to version so as to avoid multiples of the same package
-    all_transitive_deps: dict[str, str] = {}
-    for dep in direct_deps:
-        package = pkg_resources.get_distribution(dep)
-        _update_installed_dependencies_recursive(all_transitive_deps, package)
-    return all_transitive_deps
+    all_deps: dict[str, str] = {}
+    to_process = set(direct_deps)
+    processed = set()
+    # list installed packages for ease of use
+    installed_packages = {
+        dist.metadata['name'].lower()
+        for dist in importlib.metadata.distributions()}
+
+    while to_process:
+        package = to_process.pop()
+        if package in processed:
+            continue
+
+        processed.add(package)
+
+        try:
+            dist = importlib.metadata.distribution(package)
+        except importlib.metadata.PackageNotFoundError:
+            # NOTE: if not installed, we won't bother
+            #       after all, if we can save the model, clearly
+            #       everything is working
+            continue
+        requires = dist.requires or []
+
+        for req in requires:
+            match = DEP_NAME_PATTERN.match(req)
+            if match is None:
+                raise ValueError(f"Malformed dependency: {req}")
+            dep_name = match.group(0).lower()
+            if (dep_name and dep_name not in processed and
+                    dep_name in installed_packages):
+                all_deps[dep_name] = importlib.metadata.distribution(
+                    dep_name).version
+                to_process.add(dep_name)
+
+    for direct in direct_deps:
+        # remove direct dependencies if they were added
+        all_deps.pop(direct, None)
+    return all_deps
 
 
 def get_installed_dependencies(include_extras: bool) -> dict[str, str]:
@@ -89,13 +97,39 @@ def get_installed_dependencies(include_extras: bool) -> dict[str, str]:
     """
     direct_deps = get_direct_dependencies(include_extras)
     installed_packages: dict[str, str] = {}
-    for package in pkg_resources.working_set:
-        if package.project_name.lower() not in direct_deps:
+    for package in importlib.metadata.distributions():
+        req_name = package.metadata["name"].lower()
+        # NOTE: we're checking against the '-' typed package name not
+        #       the import name (which will have _ instead)
+        req_name_dashes = req_name.replace("_", "-")
+        if all(cn not in direct_deps for cn in
+               [req_name, req_name_dashes]):
             continue
-        installed_packages[package.project_name.lower()] = package.version
+        installed_packages[req_name] = package.version
     return installed_packages
 
 
+def is_dependency_installed(dependency: str) -> bool:
+    """Checks whether a dependency is installed.
+
+    This takes into account changes such as '-' vs '_'.
+    For example, `typing-extensions` is a direct dependency,
+    but its module path will be `typing_extension` and that's
+    how we can find it as an installed dependency.
+
+    Args:
+        dependency (str): The dependency in question.
+
+    Returns:
+        bool: Whether the depedency has been installed.
+    """
+    installed_deps = get_installed_dependencies(True)
+    dep_name = dependency.lower()
+    dep_name_underscores = dependency.replace("-", "_")
+    options = [dep_name, dep_name_underscores]
+    return any(option in installed_deps for option in options)
+
+
 class Environment(BaseModel, AbstractSerialisable):
     dependencies: dict[str, str]
     transitive_deps: dict[str, str]
diff --git a/tests/utils/test_envsnapshot.py b/tests/utils/test_envsnapshot.py
index fac7825..393c0b0 100644
--- a/tests/utils/test_envsnapshot.py
+++ b/tests/utils/test_envsnapshot.py
@@ -30,7 +30,7 @@ def test_dir_deps_have_no_version(self):
     def test_all_dir_deps_have_been_installed(self):
         for dep in self.dir_deps:
             with self.subTest(dep):
-                self.assertIn(dep, self.installed_deps)
+                self.assertTrue(envsnapshot.is_dependency_installed(dep))
 
     def test_all_deps_add_to_correct(self):
         # NOTE: didn't account for test/dev deps