diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 41c71873e..106274a70 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -137,13 +137,19 @@ jobs:
         Scream\Install\helpers\devcon-x64.exe install Scream\Install\driver\x64\Scream.inf *Scream
         net start audiosrv
         Get-CimInstance Win32_SoundDevice | fl *
+      timeout-minutes: 2
     - name: Sanity-check Supriya
       run: |
-        python -c "import logging, supriya; logging.getLogger('supriya').setLevel(logging.INFO); logging.basicConfig(); server = supriya.Server().boot(); server.quit(); exit()"
+        python -c "import logging, supriya; logging.getLogger('supriya').setLevel(logging.INFO); logging.basicConfig(); server = supriya.Server().boot(); exit()"
         python -c "from supriya.utils._intervals import IntervalTreeDriverEx; print(IntervalTreeDriverEx)"
     - name: Sanity-check Supriya SHM (Non-Windows)
       if: ${{ matrix.os != 'windows-latest' }}
       run: python -c "from supriya.contexts.shm import ServerSHM; print(ServerSHM)"
+    - name: Check for stray processes (Non-Windows)
+      if: ${{ matrix.os != 'windows-latest' }}
+      run: |
+        ! ( ps aux | grep scsynth | grep -v grep )
+        ! ( ps aux | grep supernova | grep -v grep )
     - name: Install Supriya test dependencies
       run: pip install -e .[test]
     - name: Install ffmpeg
diff --git a/pyproject.toml b/pyproject.toml
index b25363c00..8d47cb321 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -24,8 +24,7 @@ classifiers = [
   "Topic :: Multimedia :: Sound/Audio :: Sound Synthesis",
 ]
 dependencies = [
-  "PyYAML >= 6.0",
-  "platformdirs >= 3.1.0",
+  "platformdirs >= 3.9.1",
   "uqbar >= 0.6.9",
 ]
 description = "A Python API for SuperCollider"
@@ -100,7 +99,7 @@ exclude_lines = [
 
 [tool.isort]
 case_sensitive = true
-known_third_party = ["uqbar", "yaml"]
+known_third_party = ["uqbar"]
 profile = "black"
 skip = "supriya/__init__.py"
 
diff --git a/supriya/_version.py b/supriya/_version.py
index 07217b197..ff55c0227 100644
--- a/supriya/_version.py
+++ b/supriya/_version.py
@@ -7,5 +7,5 @@
 
 This follows black's versioning scheme.
 """
-__version_info__ = (23, "6b0")
+__version_info__ = (23, "7b0")
 __version__ = ".".join(str(x) for x in __version_info__)
diff --git a/supriya/scsynth.py b/supriya/scsynth.py
index ceb740656..e93b1f873 100644
--- a/supriya/scsynth.py
+++ b/supriya/scsynth.py
@@ -1,4 +1,5 @@
 import asyncio
+import atexit
 import enum
 import logging
 import os
@@ -280,6 +281,10 @@ def _handle_line(self, line):
 
 
 class SyncProcessProtocol(ProcessProtocol):
+    def __init__(self):
+        super().__init__()
+        atexit.register(self.quit)
+
     def boot(self, options: Options):
         if self.is_running:
             return
@@ -289,6 +294,7 @@ def boot(self, options: Options):
                 list(options),
                 stderr=subprocess.STDOUT,
                 stdout=subprocess.PIPE,
+                start_new_session=True,
             )
             start_time = time.time()
             timeout = 10
diff --git a/supriya/synthdefs/synthdefs.py b/supriya/synthdefs/synthdefs.py
index 441c705dd..0f8131c6f 100644
--- a/supriya/synthdefs/synthdefs.py
+++ b/supriya/synthdefs/synthdefs.py
@@ -6,8 +6,6 @@
 import tempfile
 from typing import Dict, List, Optional, Sequence, Tuple, Union
 
-import yaml
-
 from .. import sclang
 from ..enums import (
     BinaryOperator,
@@ -248,17 +246,20 @@ def get_parameter_name(input_, output_index=0):
                     )
                 ugen_dict[argument_name] = value
             ugens.append({ugen_name: ugen_dict or None})
-
-        result = {
-            "synthdef": {
-                "name": self.actual_name,
-                # 'hash': self.anonymous_name,
-                "ugens": ugens,
-            }
-        }
-        return yaml.dump(
-            result, default_flow_style=False, indent=4, sort_keys=False
-        ).rstrip()
+        result = [
+            "synthdef:",
+            f"    name: {self.actual_name}",
+            "    ugens:",
+        ]
+        for ugen in ugens:
+            for ugen_name, ugen_dict in ugen.items():
+                if not ugen_dict:
+                    result.append(f"    -   {ugen_name}: null")
+                    continue
+                result.append(f"    -   {ugen_name}:")
+                for parameter_name, parameter_value in ugen_dict.items():
+                    result.append(f"            {parameter_name}: {parameter_value}")
+        return "\n".join(result)
 
     ### PRIVATE METHODS ###