diff --git a/.github/workflows/phpdoc-to-github-pages b/.github/workflows/phpdoc-to-github-pages.yml
similarity index 98%
rename from .github/workflows/phpdoc-to-github-pages
rename to .github/workflows/phpdoc-to-github-pages.yml
index 69334e287..36648d157 100644
--- a/.github/workflows/phpdoc-to-github-pages
+++ b/.github/workflows/phpdoc-to-github-pages.yml
@@ -4,7 +4,6 @@ on:
   push:
     branches:
       - "main"
-  pull_request:
   workflow_dispatch:
 
 # Sets permissions of the GITHUB_TOKEN to allow deployment to GitHub Pages
diff --git a/README.md b/README.md
index 2944e391b..10565533d 100644
--- a/README.md
+++ b/README.md
@@ -10,6 +10,8 @@ This is the **[monorepo](https://en.wikipedia.org/wiki/Monorepo)** for the **mai
 
 Please read the official documentation: https://opentelemetry.io/docs/instrumentation/php/
 
+API Documentation is available here: https://open-telemetry.github.io/opentelemetry-php/
+
 ## Packages and versions
 
 | Package              | Latest                                                                                                                                                                                                                                                                                                                                                  |
diff --git a/proto/otel/composer.json b/proto/otel/composer.json
index 1ee4865e8..95a701889 100644
--- a/proto/otel/composer.json
+++ b/proto/otel/composer.json
@@ -18,7 +18,7 @@
     ],
     "require": {
         "php": "^8.0",
-        "google/protobuf": "^3.3.0"
+        "google/protobuf": "^3.22 || ^4.0"
     },
     "autoload": {
         "psr-4": {
diff --git a/src/API/Instrumentation/SpanAttribute.php b/src/API/Instrumentation/SpanAttribute.php
index b2dcd1ef8..1a9fa1d13 100644
--- a/src/API/Instrumentation/SpanAttribute.php
+++ b/src/API/Instrumentation/SpanAttribute.php
@@ -11,7 +11,7 @@
  * attribute, adding this attribute to an argument will
  * add the argument as a span attribute.
  */
-#[Attribute(Attribute::TARGET_PROPERTY)]
+#[Attribute(Attribute::TARGET_PARAMETER | Attribute::TARGET_PROPERTY)]
 final class SpanAttribute
 {
     /**
diff --git a/src/SDK/Resource/Detectors/Host.php b/src/SDK/Resource/Detectors/Host.php
index 7d74f6991..3a353cc67 100644
--- a/src/SDK/Resource/Detectors/Host.php
+++ b/src/SDK/Resource/Detectors/Host.php
@@ -54,7 +54,9 @@ private function getLinuxId(): ?string
         foreach ($paths as $path) {
             $file = $this->dir . $path;
             if (is_file($file) && is_readable($file)) {
-                return trim(file_get_contents($file));
+                $contents = file_get_contents($file);
+
+                return $contents !== false ? trim($contents) : null;
             }
         }
 
@@ -65,7 +67,9 @@ private function getBsdId(): ?string
     {
         $file = $this->dir . self::PATH_ETC_HOSTID;
         if (is_file($file) && is_readable($file)) {
-            return trim(file_get_contents($file));
+            $contents = file_get_contents($file);
+
+            return $contents !== false ? trim($contents) : null;
         }
 
         $out = exec('which kenv && kenv -q smbios.system.uuid');
diff --git a/tests/Unit/API/Instrumentation/SpanAttributeTest.php b/tests/Unit/API/Instrumentation/SpanAttributeTest.php
index d6437aa82..cc905ecde 100644
--- a/tests/Unit/API/Instrumentation/SpanAttributeTest.php
+++ b/tests/Unit/API/Instrumentation/SpanAttributeTest.php
@@ -5,7 +5,9 @@
 namespace OpenTelemetry\Tests\Unit\API\Instrumentation;
 
 use OpenTelemetry\API\Instrumentation\SpanAttribute;
+use OpenTelemetry\API\Instrumentation\WithSpan;
 use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\Attributes\DoesNotPerformAssertions;
 use PHPUnit\Framework\TestCase;
 
 #[CoversClass(SpanAttribute::class)]
@@ -16,4 +18,17 @@ public function test_with_span(): void
         $attr = new SpanAttribute('foo');
         $this->assertSame('foo', $attr->name);
     }
+
+    #[DoesNotPerformAssertions]
+    public function test_attribute_targets_parameter(): void
+    {
+        new class() {
+            #[WithSpan]
+            public function foo(
+                #[SpanAttribute] string $a,
+                #[SpanAttribute('a_better_attribute_name')] string $b,
+            ): void {
+            }
+        };
+    }
 }