diff --git a/.chloggen/fix-default-opampextension-config.yaml b/.chloggen/fix-default-opampextension-config.yaml
new file mode 100644
index 0000000000000..53e19feb7a4a4
--- /dev/null
+++ b/.chloggen/fix-default-opampextension-config.yaml
@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: bug_fix
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: opampextension
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Set the default value of `ReportsAvailableComponents` to `true`
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [40485]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: []
diff --git a/extension/opampextension/config_test.go b/extension/opampextension/config_test.go
index 3a274c325b879..10c9810c897d9 100644
--- a/extension/opampextension/config_test.go
+++ b/extension/opampextension/config_test.go
@@ -40,8 +40,9 @@ func TestUnmarshalConfig(t *testing.T) {
 			},
 			InstanceUID: "01BX5ZZKBKACTAV9WEVGEMMVRZ",
 			Capabilities: Capabilities{
-				ReportsEffectiveConfig: true,
-				ReportsHealth:          true,
+				ReportsEffectiveConfig:     true,
+				ReportsHealth:              true,
+				ReportsAvailableComponents: true,
 			},
 			PPIDPollInterval: 5 * time.Second,
 		}, cfg)
@@ -65,8 +66,9 @@ func TestUnmarshalHttpConfig(t *testing.T) {
 			},
 			InstanceUID: "01BX5ZZKBKACTAV9WEVGEMMVRZ",
 			Capabilities: Capabilities{
-				ReportsEffectiveConfig: true,
-				ReportsHealth:          true,
+				ReportsEffectiveConfig:     true,
+				ReportsHealth:              true,
+				ReportsAvailableComponents: true,
 			},
 			PPIDPollInterval: 5 * time.Second,
 		}, cfg)
diff --git a/extension/opampextension/factory.go b/extension/opampextension/factory.go
index 868c3bc85c657..3e4907c95308c 100644
--- a/extension/opampextension/factory.go
+++ b/extension/opampextension/factory.go
@@ -26,8 +26,9 @@ func createDefaultConfig() component.Config {
 	return &Config{
 		Server: &OpAMPServer{},
 		Capabilities: Capabilities{
-			ReportsEffectiveConfig: true,
-			ReportsHealth:          true,
+			ReportsEffectiveConfig:     true,
+			ReportsHealth:              true,
+			ReportsAvailableComponents: true,
 		},
 		PPIDPollInterval: 5 * time.Second,
 	}
diff --git a/extension/opampextension/opamp_agent.go b/extension/opampextension/opamp_agent.go
index 79e7272d07555..405b41c9a3f1a 100644
--- a/extension/opampextension/opamp_agent.go
+++ b/extension/opampextension/opamp_agent.go
@@ -168,6 +168,9 @@ func (o *opampAgent) Start(ctx context.Context, host component.Host) error {
 
 	if mi, ok := host.(moduleInfo); ok {
 		o.initAvailableComponents(mi.GetModuleInfos())
+	} else if o.capabilities.ReportsAvailableComponents {
+		// init empty availableComponents to not get an error when starting the opampClient
+		o.initAvailableComponents(service.ModuleInfos{})
 	}
 
 	if o.availableComponents != nil {