diff --git a/piptools/_compat/__init__.py b/piptools/_compat/__init__.py
index 9d23ddfc1..acdf3db42 100644
--- a/piptools/_compat/__init__.py
+++ b/piptools/_compat/__init__.py
@@ -19,7 +19,9 @@
     get_installed_distributions,
     install_req_from_editable,
     install_req_from_line,
+    is_dir_url,
     is_file_url,
+    is_vcs_url,
     parse_requirements,
     path_to_url,
     stdlib_pkgs,
diff --git a/piptools/_compat/pip_compat.py b/piptools/_compat/pip_compat.py
index 0259ab5bd..0a199c5f4 100644
--- a/piptools/_compat/pip_compat.py
+++ b/piptools/_compat/pip_compat.py
@@ -30,6 +30,8 @@ def do_import(module_path, subimport=None, old_path=None):
 user_cache_dir = do_import("utils.appdirs", "user_cache_dir")
 FAVORITE_HASH = do_import("utils.hashes", "FAVORITE_HASH")
 is_file_url = do_import("download", "is_file_url")
+is_dir_url = do_import("download", "is_dir_url")
+is_vcs_url = do_import("download", "is_vcs_url")
 path_to_url = do_import("download", "path_to_url")
 url_to_path = do_import("download", "url_to_path")
 PackageFinder = do_import("index", "PackageFinder")
diff --git a/piptools/repositories/pypi.py b/piptools/repositories/pypi.py
index 1397b97cf..d60d37536 100644
--- a/piptools/repositories/pypi.py
+++ b/piptools/repositories/pypi.py
@@ -19,7 +19,9 @@
     TemporaryDirectory,
     Wheel,
     contextlib,
+    is_dir_url,
     is_file_url,
+    is_vcs_url,
     path_to_url,
     url_to_path,
 )
@@ -282,21 +284,29 @@ def get_dependencies(self, ireq):
     def get_hashes(self, ireq):
         """
         Given an InstallRequirement, return a set of hashes that represent all
-        of the files for a given requirement. Editable requirements return an
+        of the files for a given requirement. Unhashable requirements return an
         empty set. Unpinned requirements raise a TypeError.
         """
-        if ireq.editable:
-            return set()
-
-        if is_url_requirement(ireq):
-            # url requirements may have been previously downloaded and cached
-            # locally by self.resolve_reqs()
-            cached_path = os.path.join(self._download_dir, ireq.link.filename)
-            if os.path.exists(cached_path):
-                cached_link = Link(path_to_url(cached_path))
-            else:
-                cached_link = ireq.link
-            return {self._get_file_hash(cached_link)}
+
+        if ireq.link:
+            link = ireq.link
+
+            if is_vcs_url(link) or (is_file_url(link) and is_dir_url(link)):
+                # Return empty set for unhashable requirements.
+                # Unhashable logic modeled on pip's
+                # RequirementPreparer.prepare_linked_requirement
+                return set()
+
+            if is_url_requirement(ireq):
+                # Directly hash URL requirements.
+                # URL requirements may have been previously downloaded and cached
+                # locally by self.resolve_reqs()
+                cached_path = os.path.join(self._download_dir, link.filename)
+                if os.path.exists(cached_path):
+                    cached_link = Link(path_to_url(cached_path))
+                else:
+                    cached_link = link
+                return {self._get_file_hash(cached_link)}
 
         if not is_pinned_requirement(ireq):
             raise TypeError("Expected pinned requirement, got {}".format(ireq))
diff --git a/tests/test_cli_compile.py b/tests/test_cli_compile.py
index 55af6c61e..5fb45ea43 100644
--- a/tests/test_cli_compile.py
+++ b/tests/test_cli_compile.py
@@ -335,12 +335,15 @@ def test_locally_available_editable_package_is_not_archived_in_cache_dir(
         ),
     ],
 )
-def test_url_package(runner, line, dependency, rewritten_line):
+@mark.parametrize(("generate_hashes",), [(True,), (False,)])
+def test_url_package(runner, line, dependency, rewritten_line, generate_hashes):
     if rewritten_line is None:
         rewritten_line = line
     with open("requirements.in", "w") as req_in:
         req_in.write(line)
-    out = runner.invoke(cli, ["-n", "--rebuild"])
+    out = runner.invoke(
+        cli, ["-n", "--rebuild"] + (["--generate-hashes"] if generate_hashes else [])
+    )
     assert out.exit_code == 0
     assert rewritten_line in out.output
     assert dependency in out.output