diff --git a/src/main/java/org/apache/maven/plugins/shade/resource/ApacheNoticeResourceTransformer.java b/src/main/java/org/apache/maven/plugins/shade/resource/ApacheNoticeResourceTransformer.java
index 4b31d329..a850a3a2 100644
--- a/src/main/java/org/apache/maven/plugins/shade/resource/ApacheNoticeResourceTransformer.java
+++ b/src/main/java/org/apache/maven/plugins/shade/resource/ApacheNoticeResourceTransformer.java
@@ -36,7 +36,6 @@
 import java.util.jar.JarOutputStream;
 
 import org.apache.maven.plugins.shade.relocation.Relocator;
-import org.codehaus.plexus.util.StringUtils;
 
 /**
  * Merges <code>META-INF/NOTICE.TXT</code> files.
@@ -106,7 +105,7 @@ public void processResource(String resource, InputStream is, List<Relocator> rel
         }
 
         BufferedReader reader;
-        if (StringUtils.isNotEmpty(encoding)) {
+        if (encoding != null && !encoding.isEmpty()) {
             reader = new BufferedReader(new InputStreamReader(is, encoding));
         } else {
             reader = new BufferedReader(new InputStreamReader(is));
@@ -178,7 +177,7 @@ public void modifyOutputStream(JarOutputStream jos) throws IOException {
         jos.putNextEntry(jarEntry);
 
         Writer writer;
-        if (StringUtils.isNotEmpty(encoding)) {
+        if (encoding != null && !encoding.isEmpty()) {
             writer = new OutputStreamWriter(jos, encoding);
         } else {
             writer = new OutputStreamWriter(jos);
diff --git a/src/main/java/org/apache/maven/plugins/shade/resource/DontIncludeResourceTransformer.java b/src/main/java/org/apache/maven/plugins/shade/resource/DontIncludeResourceTransformer.java
index 406171e8..0be64dfd 100644
--- a/src/main/java/org/apache/maven/plugins/shade/resource/DontIncludeResourceTransformer.java
+++ b/src/main/java/org/apache/maven/plugins/shade/resource/DontIncludeResourceTransformer.java
@@ -24,7 +24,6 @@
 import java.util.jar.JarOutputStream;
 
 import org.apache.maven.plugins.shade.relocation.Relocator;
-import org.codehaus.plexus.util.StringUtils;
 
 /**
  * A resource processor that prevents the inclusion of an arbitrary
@@ -36,7 +35,7 @@ public class DontIncludeResourceTransformer extends AbstractCompatibilityTransfo
     List<String> resources;
 
     public boolean canTransformResource(String r) {
-        if (StringUtils.isNotEmpty(resource) && r.endsWith(resource)) {
+        if ((resource != null && !resource.isEmpty()) && r.endsWith(resource)) {
             return true;
         }