diff --git a/pyproject.toml b/pyproject.toml
index fa8d795442..f86cab0fff 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -50,7 +50,7 @@ mp = ["mp-api>=0.37.5"]
 # phonopy 4.x changed force-constants/primitive-axis handling, breaking the
 # phonon.save -> phonopy.load round-trip used by the Grüneisen workflow
 # ("Force constants shape disagrees with crystal structure setting").
-phonons = ["phonopy>=2.43.6,<4", "seekpath>=2.0.0"]
+phonons = ["phonopy>=2.43.6,<5", "seekpath>=2.0.0"]
 lobster = ["ijson>=3.2.2", "lobsterpy>=0.6.0"]
 defects = [
     "dscribe>=1.2.0",