diff --git a/pkg/mapper/fsm/dump.go b/pkg/mapper/fsm/dump.go
index 35772f9..eb95b5f 100644
--- a/pkg/mapper/fsm/dump.go
+++ b/pkg/mapper/fsm/dump.go
@@ -35,7 +35,7 @@ func (f *FSM) DumpFSM(w io.Writer) {
 			if idx == 0 {
 				// color for metric types
 				w.Write([]byte(fmt.Sprintf("%d [color=\"#D6B656\",fillcolor=\"#FFF2CC\"];\n", len(states)-1)))
-			} else if transition.transitions == nil || len(transition.transitions) == 0 {
+			} else if len(transition.transitions) == 0 {
 				// color for end state
 				w.Write([]byte(fmt.Sprintf("%d [color=\"#82B366\",fillcolor=\"#D5E8D4\"];\n", len(states)-1)))
 			}
diff --git a/pkg/mapper/mapper.go b/pkg/mapper/mapper.go
index 52d7aac..e559201 100644
--- a/pkg/mapper/mapper.go
+++ b/pkg/mapper/mapper.go
@@ -201,10 +201,10 @@ func (m *MetricMapper) InitFromYAMLString(fileContents string) error {
 			if currentMapping.HistogramOptions == nil {
 				currentMapping.HistogramOptions = &HistogramOptions{}
 			}
-			if currentMapping.LegacyBuckets != nil && len(currentMapping.LegacyBuckets) != 0 {
+			if len(currentMapping.LegacyBuckets) != 0 {
 				currentMapping.HistogramOptions.Buckets = currentMapping.LegacyBuckets
 			}
-			if currentMapping.HistogramOptions.Buckets == nil || len(currentMapping.HistogramOptions.Buckets) == 0 {
+			if len(currentMapping.HistogramOptions.Buckets) == 0 {
 				currentMapping.HistogramOptions.Buckets = n.Defaults.HistogramOptions.Buckets
 			}
 		}
@@ -216,10 +216,10 @@ func (m *MetricMapper) InitFromYAMLString(fileContents string) error {
 			if currentMapping.SummaryOptions == nil {
 				currentMapping.SummaryOptions = &SummaryOptions{}
 			}
-			if currentMapping.LegacyQuantiles != nil && len(currentMapping.LegacyQuantiles) != 0 {
+			if len(currentMapping.LegacyQuantiles) != 0 {
 				currentMapping.SummaryOptions.Quantiles = currentMapping.LegacyQuantiles
 			}
-			if currentMapping.SummaryOptions.Quantiles == nil || len(currentMapping.SummaryOptions.Quantiles) == 0 {
+			if len(currentMapping.SummaryOptions.Quantiles) == 0 {
 				currentMapping.SummaryOptions.Quantiles = n.Defaults.SummaryOptions.Quantiles
 			}
 			if currentMapping.SummaryOptions.MaxAge == 0 {