diff --git a/src/main/java/org/apache/maven/doxia/linkcheck/DefaultLinkCheck.java b/src/main/java/org/apache/maven/doxia/linkcheck/DefaultLinkCheck.java
index d9b6713..acea4aa 100644
--- a/src/main/java/org/apache/maven/doxia/linkcheck/DefaultLinkCheck.java
+++ b/src/main/java/org/apache/maven/doxia/linkcheck/DefaultLinkCheck.java
@@ -272,7 +272,7 @@
     @Override
     public void setEncoding( String encoding )
     {
-        if ( StringUtils.isEmpty( encoding ) )
+        if ( encoding == null || encoding.isEmpty() )
         {
             throw new IllegalArgumentException( "encoding is required" );
         }
diff --git a/src/main/java/org/apache/maven/doxia/linkcheck/validation/FileLinkValidator.java b/src/main/java/org/apache/maven/doxia/linkcheck/validation/FileLinkValidator.java
index f90b77f..92fa844 100644
--- a/src/main/java/org/apache/maven/doxia/linkcheck/validation/FileLinkValidator.java
+++ b/src/main/java/org/apache/maven/doxia/linkcheck/validation/FileLinkValidator.java
@@ -27,7 +27,6 @@
 import org.apache.maven.doxia.linkcheck.model.LinkcheckFileResult;
 import org.codehaus.plexus.util.IOUtil;
 import org.codehaus.plexus.util.ReaderFactory;
-import org.codehaus.plexus.util.StringUtils;
 import org.codehaus.plexus.util.WriterFactory;
 
 /**
@@ -46,7 +45,7 @@
      */
     public FileLinkValidator( String encoding )
     {
-        if ( StringUtils.isEmpty( encoding ) )
+        if ( encoding == null || encoding.isEmpty() )
         {
             encoding = WriterFactory.UTF_8;
         }
diff --git a/src/main/java/org/apache/maven/doxia/linkcheck/validation/LinkValidatorManager.java b/src/main/java/org/apache/maven/doxia/linkcheck/validation/LinkValidatorManager.java
index a7baad8..62011f7 100644
--- a/src/main/java/org/apache/maven/doxia/linkcheck/validation/LinkValidatorManager.java
+++ b/src/main/java/org/apache/maven/doxia/linkcheck/validation/LinkValidatorManager.java
@@ -322,9 +322,9 @@
      */
     protected static boolean matchPattern( String link, String pattern )
     {
-        if ( StringUtils.isEmpty( pattern ) )
+        if ( pattern == null || pattern.isEmpty() )
         {
-            return StringUtils.isEmpty( link );
+            return link == null || link.isEmpty();
         }
 
         if ( pattern.indexOf( '*' ) == -1 )