diff --git a/poetry/puzzle/solver.py b/poetry/puzzle/solver.py
index bc787508636..35b6bd86bb5 100644
--- a/poetry/puzzle/solver.py
+++ b/poetry/puzzle/solver.py
@@ -260,9 +260,10 @@ def _solve(self, use_latest: List[str] = None) -> Tuple[List[Package], List[int]
         except SolveFailure as e:
             raise SolverProblemError(e)
 
+        # NOTE passing explicit empty array for seen to reset between invocations during update + install cycle
         results = dict(
             depth_first_search(
-                PackageNode(self._package, packages), aggregate_package_nodes
+                PackageNode(self._package, packages, seen=[]), aggregate_package_nodes
             )
         )
 
@@ -373,6 +374,7 @@ def __init__(
         self,
         package: Package,
         packages: List[Package],
+        seen: List[Package],
         previous: Optional["PackageNode"] = None,
         previous_dep: Optional[
             Union[
@@ -395,6 +397,7 @@ def __init__(
     ) -> None:
         self.package = package
         self.packages = packages
+        self.seen = seen
 
         self.previous = previous
         self.previous_dep = previous_dep
@@ -417,6 +420,12 @@ def __init__(
     def reachable(self) -> List["PackageNode"]:
         children: List[PackageNode] = []
 
+        # skip already traversed packages
+        if self.package in self.seen:
+            return []
+        else:
+            self.seen.append(self.package)
+
         if (
             self.previous_dep
             and self.previous_dep is not self.dep
@@ -453,6 +462,7 @@ def reachable(self) -> List["PackageNode"]:
                         PackageNode(
                             pkg,
                             self.packages,
+                            self.seen,
                             self,
                             dependency,
                             self.dep or dependency,
diff --git a/tests/puzzle/test_solver.py b/tests/puzzle/test_solver.py
index 37693b6333e..29e9689cf69 100644
--- a/tests/puzzle/test_solver.py
+++ b/tests/puzzle/test_solver.py
@@ -822,14 +822,14 @@ def test_solver_with_dependency_in_both_main_and_dev_dependencies(
         ],
     )
 
+    d = ops[0].package
     b = ops[1].package
     c = ops[2].package
-    d = ops[0].package
     a = ops[3].package
 
     assert d.category == "dev"
-    assert c.category == "dev"
     assert b.category == "main"
+    assert c.category == "dev"
     assert a.category == "main"
 
 
@@ -881,15 +881,15 @@ def test_solver_with_dependency_in_both_main_and_dev_dependencies_with_one_more_
     )
 
     b = ops[0].package
-    c = ops[3].package
     d = ops[1].package
     a = ops[2].package
+    c = ops[3].package
     e = ops[4].package
 
-    assert d.category == "dev"
-    assert c.category == "dev"
     assert b.category == "main"
+    assert d.category == "dev"
     assert a.category == "main"
+    assert c.category == "dev"
     assert e.category == "main"