diff --git a/cdm/core/src/main/java/ucar/nc2/dataset/VariableDS.java b/cdm/core/src/main/java/ucar/nc2/dataset/VariableDS.java
index b7b6c87d9b..691ba72e95 100644
--- a/cdm/core/src/main/java/ucar/nc2/dataset/VariableDS.java
+++ b/cdm/core/src/main/java/ucar/nc2/dataset/VariableDS.java
@@ -680,7 +680,7 @@ public boolean hasMissingValue() {
 
   @Override
   public double[] getMissingValues() {
-    return convertMissing != null ? convertMissing.getMissingValues() : new double[] {0};
+    return convertMissing != null ? convertMissing.getMissingValues() : new double[0];
   }
 
   @Override
@@ -759,7 +759,7 @@ public Number convertUnsigned(Number value) {
   }
 
   public Number convertUnsigned(Number value, DataType dataType) {
-    return unsignedConversion != null ? unsignedConversion.convertUnsigned(value, dataType) : value;
+    return unsignedConversion != null ? UnsignedConversion.convertUnsigned(value, dataType) : value;
   }
 
   @Override
diff --git a/cdm/core/src/main/java/ucar/nc2/filter/ConvertMissing.java b/cdm/core/src/main/java/ucar/nc2/filter/ConvertMissing.java
index cd2c71ac7b..73835864c7 100644
--- a/cdm/core/src/main/java/ucar/nc2/filter/ConvertMissing.java
+++ b/cdm/core/src/main/java/ucar/nc2/filter/ConvertMissing.java
@@ -5,9 +5,7 @@
 import ucar.ma2.IndexIterator;
 import ucar.nc2.Attribute;
 import ucar.nc2.constants.CDM;
-import ucar.nc2.constants.DataFormatType;
 import ucar.nc2.dataset.VariableDS;
-import ucar.nc2.iosp.netcdf3.N3iosp;
 import ucar.nc2.util.Misc;
 
 public class ConvertMissing {