diff --git a/libbeat/processors/add_process_metadata/add_process_metadata_test.go b/libbeat/processors/add_process_metadata/add_process_metadata_test.go
index 128b70a3d3c..d74297262cb 100644
--- a/libbeat/processors/add_process_metadata/add_process_metadata_test.go
+++ b/libbeat/processors/add_process_metadata/add_process_metadata_test.go
@@ -54,6 +54,22 @@ func newCGHandlerBuilder(handler testCGRsolver) processors.InitCgroupHandler {
 	}
 }
 
+func TestNilProcessor(t *testing.T) {
+	initCgroupPaths = func(rootfsMountpoint resolve.Resolver, ignoreRootCgroups bool) (processors.CGReader, error) {
+		return &processors.NilCGReader{}, nil
+	}
+
+	proc, err := newProcessMetadataProcessorWithProvider(defaultConfig(), &procCache, false)
+	require.NoError(t, err)
+
+	// make sure a nil cgroup reader doesn't blow anything up
+	unwrapped, _ := proc.(*addProcessMetadata)
+	metadata, err := unwrapped.provider.GetProcessMetadata(os.Getpid())
+	require.NoError(t, err)
+	require.NotNil(t, metadata)
+
+}
+
 func TestDefaultProcessorStartup(t *testing.T) {
 	// set initCgroupPaths to system non-test defaults
 	initCgroupPaths = func(rootfsMountpoint resolve.Resolver, ignoreRootCgroups bool) (processors.CGReader, error) {
@@ -67,7 +83,7 @@ func TestDefaultProcessorStartup(t *testing.T) {
 	unwrapped, _ := proc.(*addProcessMetadata)
 	metadata, err := unwrapped.provider.GetProcessMetadata(os.Getpid())
 	require.NoError(t, err)
-	require.NotNil(t, metadata)
+	require.NotNil(t, metadata.fields)
 }
 
 func TestAddProcessMetadata(t *testing.T) {
diff --git a/libbeat/processors/add_process_metadata/gosigar_cid_provider.go b/libbeat/processors/add_process_metadata/gosigar_cid_provider.go
index 1fa291e3528..a9c3cadee56 100644
--- a/libbeat/processors/add_process_metadata/gosigar_cid_provider.go
+++ b/libbeat/processors/add_process_metadata/gosigar_cid_provider.go
@@ -55,7 +55,7 @@ func (p gosigarCidProvider) GetCid(pid int) (result string, err error) {
 
 	cgroups, err := p.getProcessCgroups(pid)
 	if err != nil {
-		p.log.Debugf("failed to get cgroups for pid=%v: %v", pid, err)
+		return "", fmt.Errorf("failed to get cgroups for pid=%v: %v", pid, err)
 	}
 
 	cid = p.getContainerID(cgroups)