diff --git a/runner/providers/common/common.go b/runner/providers/common/common.go
index 41b50027..dfa49f0d 100644
--- a/runner/providers/common/common.go
+++ b/runner/providers/common/common.go
@@ -35,6 +35,7 @@ const (
 	RunnerActive     RunnerStatus = "active"
 )
 
+// IsValidStatus checks if the given status is valid.
 func IsValidStatus(status InstanceStatus) bool {
 	switch status {
 	case InstanceRunning, InstanceError, InstancePendingCreate,
@@ -46,3 +47,17 @@ func IsValidStatus(status InstanceStatus) bool {
 		return false
 	}
 }
+
+// IsProviderValidStatus checks if the given status is valid for the provider.
+// A provider should only return a status indicating that the instance is in a
+// lifecycle state that it can influence. The sole purpose of a provider is to
+// manage the lifecycle of an instance. Statuses that indicate an instance should
+// be created or removed, will be set by the controller.
+func IsValidProviderStatus(status InstanceStatus) bool {
+	switch status {
+	case InstanceRunning, InstanceError, InstanceStopped:
+		return true
+	default:
+		return false
+	}
+}
diff --git a/runner/providers/external/external.go b/runner/providers/external/external.go
index c8054da9..1c2ec1f2 100644
--- a/runner/providers/external/external.go
+++ b/runner/providers/external/external.go
@@ -44,21 +44,21 @@ type external struct {
 	execPath     string
 }
 
-func (e *external) validateCreateResult(inst params.Instance) error {
+func (e *external) validateResult(inst params.Instance) error {
 	if inst.ProviderID == "" {
-		return garmErrors.NewProviderError("missing provider ID after create call")
+		return garmErrors.NewProviderError("missing provider ID")
 	}
 
 	if inst.Name == "" {
-		return garmErrors.NewProviderError("missing instance name after create call")
+		return garmErrors.NewProviderError("missing instance name")
 	}
 
 	if inst.OSName == "" || inst.OSArch == "" || inst.OSType == "" {
 		// we can still function without this info (I think)
-		log.Printf("WARNING: missing OS information after create call")
+		log.Printf("WARNING: missing OS information")
 	}
-	if !providerCommon.IsValidStatus(inst.Status) {
-		return garmErrors.NewProviderError("invalid status returned (%s) after create call", inst.Status)
+	if !providerCommon.IsValidProviderStatus(inst.Status) {
+		return garmErrors.NewProviderError("invalid status returned (%s)", inst.Status)
 	}
 
 	return nil
@@ -88,7 +88,7 @@ func (e *external) CreateInstance(ctx context.Context, bootstrapParams params.Bo
 		return params.Instance{}, garmErrors.NewProviderError("failed to decode response from binary: %s", err)
 	}
 
-	if err := e.validateCreateResult(param); err != nil {
+	if err := e.validateResult(param); err != nil {
 		return params.Instance{}, garmErrors.NewProviderError("failed to validate result: %s", err)
 	}
 
@@ -137,6 +137,11 @@ func (e *external) GetInstance(ctx context.Context, instance string) (params.Ins
 	if err := json.Unmarshal(out, &param); err != nil {
 		return params.Instance{}, garmErrors.NewProviderError("failed to decode response from binary: %s", err)
 	}
+
+	if err := e.validateResult(param); err != nil {
+		return params.Instance{}, garmErrors.NewProviderError("failed to validate result: %s", err)
+	}
+
 	return param, nil
 }
 
@@ -158,6 +163,12 @@ func (e *external) ListInstances(ctx context.Context, poolID string) ([]params.I
 	if err := json.Unmarshal(out, &param); err != nil {
 		return []params.Instance{}, garmErrors.NewProviderError("failed to decode response from binary: %s", err)
 	}
+
+	for _, inst := range param {
+		if err := e.validateResult(inst); err != nil {
+			return []params.Instance{}, garmErrors.NewProviderError("failed to validate result: %s", err)
+		}
+	}
 	return param, nil
 }