diff --git a/.github/workflows/run-tests.yml b/.github/workflows/run-tests.yml
index a40c017b..163ff247 100644
--- a/.github/workflows/run-tests.yml
+++ b/.github/workflows/run-tests.yml
@@ -16,7 +16,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest]
-        version: ['3.9', '3.10', '3.11', '3.12', '3.13']
+        version: ['3.9', '3.10', '3.11', '3.12', '3.13.0']
         include:
           - version: '3.9'
             tox-env: py39,py39-mypy,py39-lint,bandit
@@ -26,7 +26,7 @@ jobs:
             tox-env: py311,py311-mypy,py311-lint,bandit
           - version: '3.12'
             tox-env: py312,py312-mypy,py312-lint,format,bandit
-          - version: '3.13'
+          - version: '3.13.0'
             tox-env: py313,py313-mypy,py313-lint,bandit
           - os: windows-latest
             version: '3.13'
diff --git a/CHANGELOG.md b/CHANGELOG.md
index bf7c39ff..0c7d265a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -28,6 +28,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
  * Fix a bug where `condp` would throw an exception if a result expression was `nil` (#1137)
  * Fix a bug where integer division which resulted in an integer would return a `fractions.Fraction` (#1140)
  * Fix a bug where `basilisp.core/time` would fail to expand with `macroexpand-all` in a nested macro call (#1143)
+ * Fix a bug where `defn` and `defmacro` forms containing multiple arities could not be emitted by macros (#1163) 
 
 ## [v0.3.2]
 ### Added
diff --git a/src/basilisp/core.lpy b/src/basilisp/core.lpy
index fff5fb61..d8e34312 100644
--- a/src/basilisp/core.lpy
+++ b/src/basilisp/core.lpy
@@ -391,7 +391,7 @@
           body   (if fmeta
                    (rest body)
                    body)
-          multi? (list? (first body))
+          multi? (seq? (first body))
           fsigs  (if multi?
                    (loop [arities body
                           sigs    []]
@@ -617,7 +617,7 @@
           fname  (if doc
                    (vary-meta name assoc :doc doc :macro true)
                    (vary-meta name assoc :macro true))
-          multi? (list? (first body))
+          multi? (seq? (first body))
           fsigs  (if multi?
                    (loop [arities body
                           sigs    []]
@@ -6528,7 +6528,7 @@
       (not (seq specs))
       (assoc groups iface methods)
 
-      (list? (first specs))
+      (seq? (first specs))
       (recur iface
              (rest specs)
              (conj methods (first specs))