diff --git a/CONTRIBUTORS b/CONTRIBUTORS
index 720327c80..f2165d9d7 100644
--- a/CONTRIBUTORS
+++ b/CONTRIBUTORS
@@ -226,6 +226,7 @@ Miha
 Mike Davis
 Mike Roberts
 mnowostawski
+Nathan Beyer
 Nick Chalko
 Nick Fortescue
 Nick Crossley
diff --git a/WHATSNEW b/WHATSNEW
index bed08bd10..204af08f7 100644
--- a/WHATSNEW
+++ b/WHATSNEW
@@ -530,6 +530,10 @@ Fixed bugs:
    overwrite each others attributes/nested elements.
    Bugzilla Report 41602.
 
+ * The Hashvalue algortihm implementation of the modified task could
+   fail to read the file(s) completely.
+   Bugzilla Report 48313.
+
 Other changes:
 --------------
 
diff --git a/contributors.xml b/contributors.xml
index 0dabc047d..44b5cb193 100644
--- a/contributors.xml
+++ b/contributors.xml
@@ -929,6 +929,10 @@
   <name>
     <last>mnowostawski</last>
   </name>
+  <name>
+    <first>Nathan</first>
+    <last>Beyer</last>
+  </name>
   <name>
     <first>Nick</first>
     <last>Chalko</last>
diff --git a/src/main/org/apache/tools/ant/types/selectors/modifiedselector/HashvalueAlgorithm.java b/src/main/org/apache/tools/ant/types/selectors/modifiedselector/HashvalueAlgorithm.java
index 10b7470d7..7f73de6be 100644
--- a/src/main/org/apache/tools/ant/types/selectors/modifiedselector/HashvalueAlgorithm.java
+++ b/src/main/org/apache/tools/ant/types/selectors/modifiedselector/HashvalueAlgorithm.java
@@ -56,11 +56,14 @@ public class HashvalueAlgorithm implements Algorithm {
                 return null;
             }
             java.io.FileInputStream fis = new java.io.FileInputStream(file);
-            byte[] content = new byte[fis.available()];
-            fis.read(content);
+            StringBuffer content = new StringBuffer();
+            byte[] buffer = new byte[256];            
+            int len = 0;
+            while ((len = fis.read(buffer, 0, len)) != -1) {
+                content.append(new String(buffer, 0, len));
+            }
             fis.close();
-            String s = new String(content);
-            int hash = s.hashCode();
+            int hash = content.toString().hashCode();
             return Integer.toString(hash);
         } catch (Exception e) {
             return null;