diff --git a/CHANGELOG.md b/CHANGELOG.md
index c0fbe90b9c32..81a76d3b0770 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 - [ENHANCEMENT] Go 1.17 is now used for all builds of the Agent. (@tpaschalis)
 
+- [BUGFIX] Fixed issue where Grafana Agent may panic if there is a very large
+  WAL loading while old WALs are being deleted or the `/agent/api/v1/targets`
+  endpoint is called. (@tpaschalis)
+
 # v0.22.0 (2022-01-13)
 
 This release has deprecations. Please read [DEPRECATION] entries and consult
diff --git a/pkg/metrics/instance/manager.go b/pkg/metrics/instance/manager.go
index a27012e63a10..a622d073b0f2 100644
--- a/pkg/metrics/instance/manager.go
+++ b/pkg/metrics/instance/manager.go
@@ -149,6 +149,9 @@ func (m *BasicManager) ListInstances() map[string]ManagedInstance {
 
 	res := make(map[string]ManagedInstance, len(m.processes))
 	for name, process := range m.processes {
+		if process == nil {
+			continue
+		}
 		res[name] = process.inst
 	}
 	return res