diff --git a/meddfntstx.rpgle b/meddfntstx.rpgle
index 66e5380..2a19085 100644
--- a/meddfntstx.rpgle
+++ b/meddfntstx.rpgle
@@ -71,6 +71,8 @@ TestInvalidHeader();
 
 TestInvalidDevice();
 
+TestInvalidMediaFile();
+
 
 dsply '----------------------------------------';
 dsply 'MEDDFN Parser Error Test completed';
@@ -84,13 +86,6 @@ return;
 //
 // TestReceiverTooSmall
 //
-// Tests parser handling of a receiver buffer that is too small
-// for a TAPE0200 header.
-//
-// Expected error:
-//
-//   MDF2005 - Receiver buffer too small
-//
 //=====================================================================
 
 dcl-proc TestReceiverTooSmall;
@@ -99,14 +94,12 @@ dcl-proc TestReceiverTooSmall;
    dsply 'Test: Receiver buffer too small';
    dsply '----------------------------------------';
 
-
    clear ReceiverBuffer;
    clear MediaDefinition;
    clear Error;
 
    ReceiverLength = 1;
 
-
    monitor;
 
       MD_ParseRetrieveBuffer(
@@ -122,21 +115,18 @@ dcl-proc TestReceiverTooSmall;
 
    endmon;
 
-
    if Error.HasError;
       dsply 'PASS Error.HasError';
    else;
       dsply 'FAIL Error.HasError';
    endif;
 
-
    if Error.MessageID = 'MDF2005';
       dsply 'PASS Error.MessageID';
    else;
       dsply 'FAIL Error.MessageID';
    endif;
 
-
    if %trim(Error.MessageData) = '';
       dsply 'PASS Error.MessageData';
    else;
@@ -150,15 +140,6 @@ end-proc;
 //
 // TestInvalidHeader
 //
-// Tests parser handling of an invalid TAPE0200 header.
-//
-// The receiver buffer is large enough for the complete header, but
-// LengthOfHeader contains an invalid value.
-//
-// Expected error:
-//
-//   MDF2001 - Invalid TAPE0200 header
-//
 //=====================================================================
 
 dcl-proc TestInvalidHeader;
@@ -172,25 +153,20 @@ dcl-proc TestInvalidHeader;
    dsply 'Test: Invalid TAPE0200 header';
    dsply '----------------------------------------';
 
-
    clear ReceiverBuffer;
    clear MediaDefinition;
    clear Error;
    clear Header;
 
-
    Header.LengthOfHeader = 0;
 
-
    %subst(
       ReceiverBuffer :
       1 :
       %size(Header)) = Header;
 
-
    ReceiverLength = %size(Header);
 
-
    monitor;
 
       MD_ParseRetrieveBuffer(
@@ -206,21 +182,18 @@ dcl-proc TestInvalidHeader;
 
    endmon;
 
-
    if Error.HasError;
       dsply 'PASS Error.HasError';
    else;
       dsply 'FAIL Error.HasError';
    endif;
 
-
    if Error.MessageID = 'MDF2001';
       dsply 'PASS Error.MessageID';
    else;
       dsply 'FAIL Error.MessageID';
    endif;
 
-
    if %trim(Error.MessageData) = '';
       dsply 'PASS Error.MessageData';
    else;
@@ -234,15 +207,6 @@ end-proc;
 //
 // TestInvalidDevice
 //
-// Tests parser handling of an invalid TAPE0200 device definition.
-//
-// The receiver contains a valid header and one device definition.
-// The device definition has an invalid structure length.
-//
-// Expected error:
-//
-//   MDF2002 - Invalid device definition
-//
 //=====================================================================
 
 dcl-proc TestInvalidDevice;
@@ -260,16 +224,118 @@ dcl-proc TestInvalidDevice;
    dsply 'Test: Invalid TAPE0200 device definition';
    dsply '----------------------------------------';
 
-
    clear ReceiverBuffer;
    clear MediaDefinition;
    clear Error;
    clear Header;
    clear Device;
 
+   Header.MaximumParallelDeviceResources = 0;
+   Header.MinimumParallelDeviceResources = 0;
+   Header.OffsetToFirstDeviceDefinition =
+      %size(Header);
+   Header.NumberOfDeviceDefinitions = 1;
+   Header.LengthOfHeader =
+      %size(Header);
+   Header.DeviceAllocation =
+      MD_DeviceAllocateAll;
+   Header.SaveFormat =
+      MD_SaveFormatSerial;
+
+   Device.OffsetToNextDeviceDefinition = 0;
+   Device.DeviceName = 'TAPMLBBRMS';
+   Device.OffsetToFirstMediaFileDefinition =
+      %size(Device);
+   Device.NumberOfMediaFileDefinitions = 1;
+
+   // Deliberately invalid.
+   Device.LengthOfDeviceDefinition = 0;
+
+   %subst(
+      ReceiverBuffer :
+      1 :
+      %size(Header)) = Header;
+
+   %subst(
+      ReceiverBuffer :
+      %size(Header) + 1 :
+      %size(Device)) = Device;
+
+   ReceiverLength =
+      %size(Header)
+      + %size(Device);
+
+   monitor;
+
+      MD_ParseRetrieveBuffer(
+         ReceiverBuffer :
+         ReceiverLength :
+         MediaDefinition :
+         Error);
+
+   on-error;
+
+      dsply 'FAIL Unexpected runtime error';
+      return;
+
+   endmon;
+
+   if Error.HasError;
+      dsply 'PASS Error.HasError';
+   else;
+      dsply 'FAIL Error.HasError';
+   endif;
+
+   if Error.MessageID = 'MDF2002';
+      dsply 'PASS Error.MessageID';
+   else;
+      dsply 'FAIL Error.MessageID';
+   endif;
+
+   if %trim(Error.MessageData) = '';
+      dsply 'PASS Error.MessageData';
+   else;
+      dsply 'FAIL Error.MessageData';
+   endif;
+
+end-proc;
+
+
+//=====================================================================
+//
+// TestInvalidMediaFile
+//
+//=====================================================================
+
+dcl-proc TestInvalidMediaFile;
+
+   dcl-ds Header
+      likeds(MD_Tape0200Header_T)
+      inz;
+
+   dcl-ds Device
+      likeds(MD_Tape0200DeviceDefinition_T)
+      inz;
+
+   dcl-ds MediaFile
+      likeds(MD_Tape0200MediaFileDefinition_T)
+      inz;
+
+
+   dsply '----------------------------------------';
+   dsply 'Test: Invalid TAPE0200 media file definition';
+   dsply '----------------------------------------';
+
+   clear ReceiverBuffer;
+   clear MediaDefinition;
+   clear Error;
+   clear Header;
+   clear Device;
+   clear MediaFile;
+
 
    //===============================================================
-   // Valid header
+   // Header
    //===============================================================
 
    Header.MaximumParallelDeviceResources = 0;
@@ -292,7 +358,7 @@ dcl-proc TestInvalidDevice;
 
 
    //===============================================================
-   // Invalid device definition
+   // Device
    //===============================================================
 
    Device.OffsetToNextDeviceDefinition = 0;
@@ -304,12 +370,32 @@ dcl-proc TestInvalidDevice;
 
    Device.NumberOfMediaFileDefinitions = 1;
 
-   // Deliberately invalid.
-   Device.LengthOfDeviceDefinition = 0;
+   Device.LengthOfDeviceDefinition =
+      %size(Device);
 
 
    //===============================================================
-   // Header and device into receiver buffer
+   // Media file
+   //===============================================================
+
+   MediaFile.OffsetToNextMediaFileDefinition = 0;
+
+   MediaFile.SequenceNumber = 1;
+
+   MediaFile.NumberOfVolumeIdentifiers = 0;
+
+   MediaFile.OffsetToVolumeIdentifierArray = 0;
+
+   MediaFile.LengthOfVolumeIdentifier = 0;
+
+   MediaFile.StartingVolumeArrayElement = 0;
+
+   // Deliberately invalid.
+   MediaFile.LengthOfMediaFileDefinition = 0;
+
+
+   //===============================================================
+   // Build receiver buffer
    //===============================================================
 
    %subst(
@@ -317,18 +403,29 @@ dcl-proc TestInvalidDevice;
       1 :
       %size(Header)) = Header;
 
-
    %subst(
       ReceiverBuffer :
       %size(Header) + 1 :
       %size(Device)) = Device;
 
+   %subst(
+      ReceiverBuffer :
+      %size(Header)
+      + %size(Device)
+      + 1 :
+      %size(MediaFile)) = MediaFile;
+
 
    ReceiverLength =
       %size(Header)
-      + %size(Device);
+      + %size(Device)
+      + %size(MediaFile);
 
 
+   //===============================================================
+   // Execute parser
+   //===============================================================
+
    monitor;
 
       MD_ParseRetrieveBuffer(
@@ -345,6 +442,10 @@ dcl-proc TestInvalidDevice;
    endmon;
 
 
+   //===============================================================
+   // Result
+   //===============================================================
+
    if Error.HasError;
       dsply 'PASS Error.HasError';
    else;
@@ -352,7 +453,7 @@ dcl-proc TestInvalidDevice;
    endif;
 
 
-   if Error.MessageID = 'MDF2002';
+   if Error.MessageID = 'MDF2003';
       dsply 'PASS Error.MessageID';
    else;
       dsply 'FAIL Error.MessageID';