diff --git a/poetry.lock b/poetry.lock
index f2963ea..eea0b9f 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -1,10 +1,9 @@
-# This file is automatically @generated by Poetry 1.4.1 and should not be changed by hand.
+# This file is automatically @generated by Poetry 1.8.2 and should not be changed by hand.
 
 [[package]]
 name = "astropy"
 version = "5.2.1"
 description = "Astronomy and astrophysics core library"
-category = "main"
 optional = false
 python-versions = ">=3.8"
 files = [
@@ -58,7 +57,6 @@ test-all = ["coverage[toml]", "ipython (>=4.2)", "objgraph", "pytest (>=7.0)", "
 name = "attrs"
 version = "22.2.0"
 description = "Classes Without Boilerplate"
-category = "dev"
 optional = false
 python-versions = ">=3.6"
 files = [
@@ -77,7 +75,6 @@ tests-no-zope = ["cloudpickle", "cloudpickle", "hypothesis", "hypothesis", "mypy
 name = "certifi"
 version = "2022.12.7"
 description = "Python package for providing Mozilla's CA Bundle."
-category = "dev"
 optional = false
 python-versions = ">=3.6"
 files = [
@@ -89,7 +86,6 @@ files = [
 name = "charset-normalizer"
 version = "3.0.1"
 description = "The Real First Universal Charset Detector. Open, modern and actively maintained alternative to Chardet."
-category = "dev"
 optional = false
 python-versions = "*"
 files = [
@@ -187,7 +183,6 @@ files = [
 name = "colorama"
 version = "0.4.6"
 description = "Cross-platform colored terminal text."
-category = "dev"
 optional = false
 python-versions = "!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*,!=3.4.*,!=3.5.*,!=3.6.*,>=2.7"
 files = [
@@ -199,7 +194,6 @@ files = [
 name = "coverage"
 version = "6.5.0"
 description = "Code coverage measurement for Python"
-category = "dev"
 optional = false
 python-versions = ">=3.7"
 files = [
@@ -262,7 +256,6 @@ toml = ["tomli"]
 name = "coveralls"
 version = "3.3.1"
 description = "Show coverage stats online via coveralls.io"
-category = "dev"
 optional = false
 python-versions = ">= 3.5"
 files = [
@@ -271,7 +264,7 @@ files = [
 ]
 
 [package.dependencies]
-coverage = ">=4.1,<6.0.0 || >6.1,<6.1.1 || >6.1.1,<7.0"
+coverage = ">=4.1,<6.0.dev0 || >6.1,<6.1.1 || >6.1.1,<7.0"
 docopt = ">=0.6.1"
 requests = ">=1.0.0"
 
@@ -282,7 +275,6 @@ yaml = ["PyYAML (>=3.10)"]
 name = "docopt"
 version = "0.6.2"
 description = "Pythonic argument parser, that will make you smile"
-category = "dev"
 optional = false
 python-versions = "*"
 files = [
@@ -293,7 +285,6 @@ files = [
 name = "exceptiongroup"
 version = "1.1.0"
 description = "Backport of PEP 654 (exception groups)"
-category = "dev"
 optional = false
 python-versions = ">=3.7"
 files = [
@@ -308,7 +299,6 @@ test = ["pytest (>=6)"]
 name = "fitsio"
 version = "1.1.8"
 description = "A full featured python library to read from and write to FITS files."
-category = "main"
 optional = true
 python-versions = "*"
 files = [
@@ -322,7 +312,6 @@ numpy = "*"
 name = "idna"
 version = "3.4"
 description = "Internationalized Domain Names in Applications (IDNA)"
-category = "dev"
 optional = false
 python-versions = ">=3.5"
 files = [
@@ -334,7 +323,6 @@ files = [
 name = "iniconfig"
 version = "2.0.0"
 description = "brain-dead simple config-ini parsing"
-category = "dev"
 optional = false
 python-versions = ">=3.7"
 files = [
@@ -346,7 +334,6 @@ files = [
 name = "mypy"
 version = "1.0.1"
 description = "Optional static typing for Python"
-category = "dev"
 optional = false
 python-versions = ">=3.7"
 files = [
@@ -393,7 +380,6 @@ reports = ["lxml"]
 name = "mypy-extensions"
 version = "1.0.0"
 description = "Type system extensions for programs checked with the mypy type checker."
-category = "dev"
 optional = false
 python-versions = ">=3.5"
 files = [
@@ -405,7 +391,6 @@ files = [
 name = "numpy"
 version = "1.24.2"
 description = "Fundamental package for array computing in Python"
-category = "main"
 optional = false
 python-versions = ">=3.8"
 files = [
@@ -443,7 +428,6 @@ files = [
 name = "packaging"
 version = "23.0"
 description = "Core utilities for Python packages"
-category = "main"
 optional = false
 python-versions = ">=3.7"
 files = [
@@ -455,7 +439,6 @@ files = [
 name = "pluggy"
 version = "1.0.0"
 description = "plugin and hook calling mechanisms for python"
-category = "dev"
 optional = false
 python-versions = ">=3.6"
 files = [
@@ -471,7 +454,6 @@ testing = ["pytest", "pytest-benchmark"]
 name = "pyerfa"
 version = "2.0.0.1"
 description = "Python bindings for ERFA"
-category = "main"
 optional = false
 python-versions = ">=3.7"
 files = [
@@ -517,7 +499,6 @@ test = ["pytest", "pytest-doctestplus (>=0.7)"]
 name = "pytest"
 version = "7.2.1"
 description = "pytest: simple powerful testing with Python"
-category = "dev"
 optional = false
 python-versions = ">=3.7"
 files = [
@@ -541,7 +522,6 @@ testing = ["argcomplete", "hypothesis (>=3.56)", "mock", "nose", "pygments (>=2.
 name = "pyyaml"
 version = "6.0"
 description = "YAML parser and emitter for Python"
-category = "main"
 optional = false
 python-versions = ">=3.6"
 files = [
@@ -591,7 +571,6 @@ files = [
 name = "requests"
 version = "2.28.2"
 description = "Python HTTP for Humans."
-category = "dev"
 optional = false
 python-versions = ">=3.7, <4"
 files = [
@@ -613,7 +592,6 @@ use-chardet-on-py3 = ["chardet (>=3.0.2,<6)"]
 name = "tomli"
 version = "2.0.1"
 description = "A lil' TOML parser"
-category = "dev"
 optional = false
 python-versions = ">=3.7"
 files = [
@@ -625,7 +603,6 @@ files = [
 name = "typing-extensions"
 version = "4.5.0"
 description = "Backported and Experimental Type Hints for Python 3.7+"
-category = "dev"
 optional = false
 python-versions = ">=3.7"
 files = [
@@ -637,7 +614,6 @@ files = [
 name = "urllib3"
 version = "1.26.14"
 description = "HTTP library with thread-safe connection pooling, file post, and more."
-category = "dev"
 optional = false
 python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, !=3.5.*"
 files = [
@@ -656,4 +632,4 @@ fits = ["fitsio"]
 [metadata]
 lock-version = "2.0"
 python-versions = "^3.9"
-content-hash = "855474db28cd1931b303fa412e9e083d11fcf4b25e8f86ba07c004567f883fc8"
+content-hash = "dd454c68a1c41f1f2f304154fd68cad199e7434887e6ecdf29ff90c43a62eab2"
diff --git a/pyproject.toml b/pyproject.toml
index 509041a..e2fdbbd 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -13,8 +13,8 @@ maintainers = [
 [tool.poetry.dependencies]
 python = "^3.9"
 numpy = "^1.24.2"
-astropy = "^5.2.1"
-fitsio = {version="^1.1.8", optional=true}
+astropy = ">=5"
+fitsio = {version="^1", optional=true}
 
 [tool.poetry.extras]
 fits = ["fitsio"]