diff --git a/var/spack/repos/builtin/packages/arbor/package.py b/var/spack/repos/builtin/packages/arbor/package.py
index 9adacf477f..94b9e78cfa 100644
--- a/var/spack/repos/builtin/packages/arbor/package.py
+++ b/var/spack/repos/builtin/packages/arbor/package.py
@@ -10,13 +10,14 @@ class Arbor(CMakePackage, CudaPackage):
     """Arbor is a high-performance library for computational neuroscience
     simulations."""
 
-    homepage = "https://github.com/arbor-sim/arbor/"
-    git      = "https://github.com/arbor-sim/arbor.git"
-    url      = "https://github.com/arbor-sim/arbor/releases/download/v0.5/arbor-v0.5-full.tar.gz"
-    maintainers = ['bcumming', 'halfflat']
+    homepage = 'https://arbor-sim.org'
+    git      = 'https://github.com/arbor-sim/arbor.git'
+    url      = 'https://github.com/arbor-sim/arbor/releases/download/v0.5.2/arbor-v0.5.2-full.tar.gz'
+    maintainers = ['bcumming', 'brenthuisman', 'haampie', 'halfflat']
 
     version('master', branch='master', submodules=True)
-    version('0.5', 'd0c8a4c7f97565d7c30493c66249be794d1dc424de266fc79cecbbf0e313df59')
+    version('0.5.2', sha256='290e2ad8ca8050db1791cabb6b431e7c0409c305af31b559e397e26b300a115d', url='https://github.com/arbor-sim/arbor/releases/download/v0.5.2/arbor-v0.5.2-full.tar.gz')
+    version('0.5', sha256='d0c8a4c7f97565d7c30493c66249be794d1dc424de266fc79cecbbf0e313df59', url='https://github.com/arbor-sim/arbor/releases/download/v0.5/arbor-v0.5-full.tar.gz')
 
     variant('assertions', default=False, description='Enable arb_assert() assertions in code.')
     variant('doc', default=False, description='Build documentation.')
@@ -25,9 +26,9 @@ class Arbor(CMakePackage, CudaPackage):
     variant('python', default=True, description='Enable Python frontend support')
     variant('vectorize', default=False, description='Enable vectorization of computational kernels')
 
-    # https://arbor.readthedocs.io/en/latest/install/build_install.html?highlight=requirements#compilers
+    # https://docs.arbor-sim.org/en/latest/install/build_install.html?highlight=requirements#compilers
     conflicts('%gcc@:8.3')
-    conflicts('%clang@:8.0')
+    conflicts('%clang@:7')
     # Cray compiler v9.2 and later is Clang-based.
     conflicts('%cce@:9.1')
     conflicts('%intel')
@@ -47,7 +48,7 @@ class Arbor(CMakePackage, CudaPackage):
     extends('python', when='+python')
     depends_on('python@3.6:', when="+python", type=('build', 'run'))
     depends_on('py-numpy', when='+python', type=('build', 'run'))
-    depends_on('py-pybind11', when='+python', type=('build', 'run'))
+    depends_on('py-pybind11@2.6:', when='+python', type=('build', 'run'))
 
     # sphinx based documentation
     depends_on('python@3.6:', when="+doc", type='build')
@@ -70,7 +71,11 @@ def cmake_args(self):
         if '+cuda' in self.spec:
             args.append('-DARB_GPU=cuda')
 
-        # rely on spack's compiler wrapper to set architecture
-        args.append('-DARB_ARCH=')
+        # query spack for the architecture-specific compiler flags set by its wrapper
+        args.append('-DARB_ARCH=none')
+        opt_flags = self.spec.target.optimization_flags(
+            self.spec.compiler.name,
+            self.spec.compiler.version)
+        args.append('-DARB_CXX_FLAGS_TARGET=' + opt_flags)
 
         return args