diff --git a/src/main/org/apache/tools/ant/taskdefs/Replace.java b/src/main/org/apache/tools/ant/taskdefs/Replace.java
index 06e55ac64..0c2252eaa 100644
--- a/src/main/org/apache/tools/ant/taskdefs/Replace.java
+++ b/src/main/org/apache/tools/ant/taskdefs/Replace.java
@@ -402,25 +402,11 @@ public class Replace extends MatchingTask {
             BufferedReader br = new BufferedReader(reader);
             BufferedWriter bw = new BufferedWriter(writer);
 
-            // read the entire file into a StringBuffer
-            //   size of work buffer may be bigger than needed
-            //   when multibyte characters exist in the source file
-            //   but then again, it might be smaller than needed on
-            //   platforms like Windows where length can't be trusted
-            int fileLengthInBytes = (int) src.length();
-            StringBuffer tmpBuf = new StringBuffer(fileLengthInBytes);
-            int readChar = 0;
-            int totread = 0;
-            while (true) {
-                readChar = br.read();
-                if (readChar < 0) { break; }
-                tmpBuf.append((char) readChar);
-                totread++;
+            String buf = fileUtils.readFully(br);
+            if (buf == null) {
+                buf = "";
             }
 
-            // create a String so we can use indexOf
-            String buf = tmpBuf.toString();
-
             //Preserve original string (buf) so we can compare the result
             String newString = new String(buf);
 
diff --git a/src/main/org/apache/tools/ant/taskdefs/optional/ReplaceRegExp.java b/src/main/org/apache/tools/ant/taskdefs/optional/ReplaceRegExp.java
index cd7895a6d..ba1372c12 100644
--- a/src/main/org/apache/tools/ant/taskdefs/optional/ReplaceRegExp.java
+++ b/src/main/org/apache/tools/ant/taskdefs/optional/ReplaceRegExp.java
@@ -417,6 +417,9 @@ public class ReplaceRegExp extends Task {
                 pw.flush();
             } else {
                 String buf = fileUtils.readFully(br);
+                if (buf == null) {
+                    buf = "";
+                }
 
                 String res = doReplace(regex, subs, buf, options);