diff --git a/var/spack/repos/builtin/packages/py-pymc3/package.py b/var/spack/repos/builtin/packages/py-pymc3/package.py
index fd4b4b785dc..5dd08bc7c09 100644
--- a/var/spack/repos/builtin/packages/py-pymc3/package.py
+++ b/var/spack/repos/builtin/packages/py-pymc3/package.py
@@ -22,7 +22,9 @@ class PyPymc3(PythonPackage):
     depends_on("py-setuptools", type="build")
     depends_on("py-arviz@0.4.1:", type=("build", "run"))
     depends_on("py-theano@1.0.4:", type=("build", "run"))
-    depends_on("py-numpy@1.13.0:", type=("build", "run"))
+    # numpy 2 support added in pymc 5.21, pymc3 is the legacy package
+    # https://github.com/pymc-devs/pymc/pull/7688
+    depends_on("py-numpy@1.13.0:1", type=("build", "run"))
     depends_on("py-scipy@0.18.1:", type=("build", "run"))
     depends_on("py-pandas@0.18.0:", type=("build", "run"))
     depends_on("py-patsy@0.4.0:", type=("build", "run"))