diff --git a/src/pngimage.cpp b/src/pngimage.cpp
index cea96e1c27..599fd61df0 100644
--- a/src/pngimage.cpp
+++ b/src/pngimage.cpp
@@ -552,8 +552,7 @@ namespace Exiv2 {
         // Write PNG Signature.
         if (outIo.write(pngSignature, 8) != 8) throw Error(kerImageWriteFailed);
 
-        DataBuf cheaderBuf(9);   // Chunk header : 4 bytes (data size) + 4 bytes (chunk type) + nul
-        cheaderBuf.pData_[8] = 0;
+        DataBuf cheaderBuf(8);       // Chunk header : 4 bytes (data size) + 4 bytes (chunk type).
 
         while(!io_->eof())
         {
diff --git a/test/data/png-test.out b/test/data/png-test.out
index cc8e23435b..ced4cd3f22 100644
--- a/test/data/png-test.out
+++ b/test/data/png-test.out
@@ -11,7 +11,6 @@ STRUCTURE OF PNG FILE: 1343_empty.png
  address | chunk |  length | data                           | checksum
        8 | IHDR  |      13 | .......d....                   | 0x4ce4e85c
       33 | iTXt  |      39 | Description.....x.K.H.KOMQH... | 0xe0a1c8ce
-changed comment
       84 | sRGB  |       1 |                                | 0xaece1ce9
       97 | gAMA  |       4 | ....                           | 0x0bfc6105
      113 | pHYs  |       9 | .........                      | 0xc76fa864
@@ -32,7 +31,6 @@ STRUCTURE OF PNG FILE: 1343_comment.png
  address | chunk |  length | data                           | checksum
        8 | IHDR  |      13 | .......d....                   | 0x4ce4e85c
       33 | iTXt  |      39 | Description.....x.K.H.KOMQH... | 0xe0a1c8ce
-changed comment
       84 | sRGB  |       1 |                                | 0xaece1ce9
       97 | gAMA  |       4 | ....                           | 0x0bfc6105
      113 | pHYs  |       9 | .........                      | 0xc76fa864
@@ -48,14 +46,6 @@ STRUCTURE OF PNG FILE: 1343_exif.png
       62 | pHYs  |       9 | .........                      | 0xc76fa864
       83 | IDAT  |     257 | x^..1..0......t.....h......z.. | 0x64465429
      352 | eXIf  |     108 | MM.*.................J........ | 0x764e86e1
-  STRUCTURE OF TIFF FILE (MM): MemIo
-   address |    tag                              |      type |    count |    offset | value
-        10 | 0x010e ImageDescription             |     ASCII |       17 |        74 | Can you read me?
-        22 | 0x011a XResolution                  |  RATIONAL |        1 |        92 | 72/1
-        34 | 0x011b YResolution                  |  RATIONAL |        1 |       100 | 72/1
-        46 | 0x0128 ResolutionUnit               |     SHORT |        1 |           | 2
-        58 | 0x0213 YCbCrPositioning             |     SHORT |        1 |           | 1
-  END MemIo
      472 | IEND  |       0 |                                | 0xae426082
 
 Exif.Image.ImageDescription                  Ascii      17  Can you read me?
@@ -67,16 +57,7 @@ STRUCTURE OF PNG FILE: 1343_exif.png
  address | chunk |  length | data                           | checksum
        8 | IHDR  |      13 | .......d....                   | 0x4ce4e85c
       33 | iTXt  |      39 | Description.....x.K.H.KOMQH... | 0xe0a1c8ce
-changed comment
       84 | zTXt  |     145 | Raw profile type exif..x.U.... | 0x2f6d89e8
-  STRUCTURE OF TIFF FILE (II): MemIo
-   address |    tag                              |      type |    count |    offset | value
-        10 | 0x010e ImageDescription             |     ASCII |       17 |        74 | Can you read me?
-        22 | 0x011a XResolution                  |  RATIONAL |        1 |        92 | 72/1
-        34 | 0x011b YResolution                  |  RATIONAL |        1 |       100 | 72/1
-        46 | 0x0128 ResolutionUnit               |     SHORT |        1 |           | 2
-        58 | 0x0213 YCbCrPositioning             |     SHORT |        1 |           | 1
-  END MemIo
      241 | sRGB  |       1 |                                | 0xaece1ce9
      254 | gAMA  |       4 | ....                           | 0x0bfc6105
      270 | pHYs  |       9 | .........                      | 0xc76fa864
diff --git a/test/png-test.sh b/test/png-test.sh
index 9acb1df3e9..8044c00e38 100755
--- a/test/png-test.sh
+++ b/test/png-test.sh
@@ -9,7 +9,7 @@ source ./functions.source
     copyTestFiles  $files
     for file in $files ; do
         for  i in 1 2 ; do 
-            runTest exiv2 -pR   $file
+            runTest exiv2 -pS   $file
             runTest exiv2 -pc   $file
             runTest exiv2 -pa   $file
             runTest exiv2 -c  'changed comment' $file
diff --git a/tests/bash_tests/testcases.py b/tests/bash_tests/testcases.py
index bd05705dc0..3ad0df2b7f 100644
--- a/tests/bash_tests/testcases.py
+++ b/tests/bash_tests/testcases.py
@@ -875,7 +875,7 @@ def png_test(self):
 #       runTest exiv2 -c 'comment in Reagan to hide non UTF-8 bytes'
 #       for file in $files ; do
 #           for  i in 1 2 ; do 
-#               runTest exiv2 -pR   $file
+#               runTest exiv2 -pS   $file
 #               runTest exiv2 -pc   $file
 #               runTest exiv2 -pa   $file
 #               runTest exiv2 -c  'changed comment' $file
@@ -890,8 +890,10 @@ def png_test(self):
         for file in files:
             BT.copyTestFile(file)
             for i in [1,2]:
-                out  += BT.Executer('exiv2 -pR    {file}', vars())
+                out  += BT.Executer('exiv2 -pS    {file}', vars())
                 out  += BT.Executer('exiv2 -pc    {file}', vars())
+                if i ==1:
+                  out+= ''
                 out  += BT.Executer('exiv2 -pa    {file}', vars())
                 out  += BT.Executer('exiv2 -c "changed comment" {file}', vars())