diff --git a/.github/workflows/pytest-legacy.yml b/.github/workflows/pytest-legacy.yml
index 7a367a17a..d542fb8a2 100644
--- a/.github/workflows/pytest-legacy.yml
+++ b/.github/workflows/pytest-legacy.yml
@@ -47,7 +47,7 @@ jobs:
       run: |
         poetry add iam-units@2020.4.21
         poetry add matplotlib@3.6.0
-        poetry add numpy@1.23.2
+        poetry add numpy@1.26.0
         poetry add pandas@2.1.2
         poetry add pint@0.13
         poetry add xlrd@2.0.1 --group optional_io_formats
diff --git a/poetry.lock b/poetry.lock
index 030bd1334..3c654fcc9 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -4450,4 +4450,4 @@ testing = ["big-O", "jaraco.functools", "jaraco.itertools", "more-itertools", "p
 [metadata]
 lock-version = "2.0"
 python-versions = ">=3.10, <3.13"
-content-hash = "e186befb326b41beda98890f420992c2130e7df3e42f0d44ae3a3bc8731b9aea"
+content-hash = "4702fd674596f37596ef2d7d9d259a99003a17c7d863b0c99ae563a60702dd64"
diff --git a/pyproject.toml b/pyproject.toml
index d2c367dae..e56275293 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -48,7 +48,7 @@ python = ">=3.10, <3.13"
 iam-units = ">=2020.4.21"
 ixmp4 = ">=0.7.1"
 matplotlib = ">=3.6.0"
-numpy = ">=1.23.2"
+numpy = ">=1.26.0"
 openpyxl = ">=3.1.2"
 pandas = ">=2.1.2"
 Pint = ">=0.13"