diff --git a/taglib/ape/apefile.cpp b/taglib/ape/apefile.cpp
index c0e32c33..9f298aaf 100644
--- a/taglib/ape/apefile.cpp
+++ b/taglib/ape/apefile.cpp
@@ -70,13 +70,13 @@ public:
   }
 
   long APELocation;
-  unsigned int APESize;
+  long APESize;
 
   long ID3v1Location;
 
   ID3v2::Header *ID3v2Header;
   long ID3v2Location;
-  unsigned int ID3v2Size;
+  long ID3v2Size;
 
   TagUnion tag;
 
@@ -186,7 +186,7 @@ bool APE::File::save()
     insert(data, d->APELocation, d->APESize);
 
     if(d->ID3v1Location >= 0)
-      d->ID3v1Location += (data.size() - d->APESize);
+      d->ID3v1Location += (static_cast<long>(data.size()) - d->APESize);
 
     d->APESize = data.size();
   }
diff --git a/taglib/flac/flacfile.cpp b/taglib/flac/flacfile.cpp
index 2e58e848..fb7418d1 100644
--- a/taglib/flac/flacfile.cpp
+++ b/taglib/flac/flacfile.cpp
@@ -80,7 +80,7 @@ public:
 
   const ID3v2::FrameFactory *ID3v2FrameFactory;
   long ID3v2Location;
-  unsigned int ID3v2OriginalSize;
+  long ID3v2OriginalSize;
 
   long ID3v1Location;
 
@@ -226,10 +226,10 @@ bool FLAC::File::save()
 
   insert(data, d->flacStart, originalLength);
 
-  d->streamStart += (data.size() - originalLength);
+  d->streamStart += (static_cast<long>(data.size()) - originalLength);
 
   if(d->ID3v1Location >= 0)
-    d->ID3v1Location += (data.size() - originalLength);
+    d->ID3v1Location += (static_cast<long>(data.size()) - originalLength);
 
   // Update ID3 tags
 
@@ -243,11 +243,11 @@ bool FLAC::File::save()
     data = ID3v2Tag()->render();
     insert(data, d->ID3v2Location, d->ID3v2OriginalSize);
 
-    d->flacStart   += (data.size() - d->ID3v2OriginalSize);
-    d->streamStart += (data.size() - d->ID3v2OriginalSize);
+    d->flacStart   += (static_cast<long>(data.size()) - d->ID3v2OriginalSize);
+    d->streamStart += (static_cast<long>(data.size()) - d->ID3v2OriginalSize);
 
     if(d->ID3v1Location >= 0)
-      d->ID3v1Location += (data.size() - d->ID3v2OriginalSize);
+      d->ID3v1Location += (static_cast<long>(data.size()) - d->ID3v2OriginalSize);
 
     d->ID3v2OriginalSize = data.size();
   }
diff --git a/taglib/mpc/mpcfile.cpp b/taglib/mpc/mpcfile.cpp
index b586bbf6..daf24c8f 100644
--- a/taglib/mpc/mpcfile.cpp
+++ b/taglib/mpc/mpcfile.cpp
@@ -62,13 +62,13 @@ public:
   }
 
   long APELocation;
-  unsigned int APESize;
+  long APESize;
 
   long ID3v1Location;
 
   ID3v2::Header *ID3v2Header;
   long ID3v2Location;
-  unsigned int ID3v2Size;
+  long ID3v2Size;
 
   TagUnion tag;
 
@@ -193,7 +193,7 @@ bool MPC::File::save()
     insert(data, d->APELocation, d->APESize);
 
     if(d->ID3v1Location >= 0)
-      d->ID3v1Location += (data.size() - d->APESize);
+      d->ID3v1Location += (static_cast<long>(data.size()) - d->APESize);
 
     d->APESize = data.size();
   }
diff --git a/taglib/mpeg/mpegfile.cpp b/taglib/mpeg/mpegfile.cpp
index e1910c2d..4fc3533f 100644
--- a/taglib/mpeg/mpegfile.cpp
+++ b/taglib/mpeg/mpegfile.cpp
@@ -82,10 +82,10 @@ public:
   const ID3v2::FrameFactory *ID3v2FrameFactory;
 
   long ID3v2Location;
-  unsigned int ID3v2OriginalSize;
+  long ID3v2OriginalSize;
 
   long APELocation;
-  unsigned int APEOriginalSize;
+  long APEOriginalSize;
 
   long ID3v1Location;
 
@@ -274,7 +274,7 @@ bool MPEG::File::save(int tags, bool stripOthers, int id3v2Version, bool duplica
       insert(data, d->APELocation, d->APEOriginalSize);
 
       if(d->ID3v1Location >= 0)
-        d->ID3v1Location += (data.size() - d->APEOriginalSize);
+        d->ID3v1Location += (static_cast<long>(data.size()) - d->APEOriginalSize);
 
       d->APEOriginalSize = data.size();
     }
diff --git a/taglib/trueaudio/trueaudiofile.cpp b/taglib/trueaudio/trueaudiofile.cpp
index 27dc606d..fc123ba3 100644
--- a/taglib/trueaudio/trueaudiofile.cpp
+++ b/taglib/trueaudio/trueaudiofile.cpp
@@ -64,7 +64,7 @@ public:
 
   const ID3v2::FrameFactory *ID3v2FrameFactory;
   long ID3v2Location;
-  unsigned int ID3v2OriginalSize;
+  long ID3v2OriginalSize;
 
   long ID3v1Location;
 
@@ -169,7 +169,7 @@ bool TrueAudio::File::save()
     insert(data, d->ID3v2Location, d->ID3v2OriginalSize);
 
     if(d->ID3v1Location >= 0)
-      d->ID3v1Location += (data.size() - d->ID3v2OriginalSize);
+      d->ID3v1Location += (static_cast<long>(data.size()) - d->ID3v2OriginalSize);
 
     d->ID3v2OriginalSize = data.size();
   }
diff --git a/taglib/wavpack/wavpackfile.cpp b/taglib/wavpack/wavpackfile.cpp
index 909c5590..ef92f4bd 100644
--- a/taglib/wavpack/wavpackfile.cpp
+++ b/taglib/wavpack/wavpackfile.cpp
@@ -62,7 +62,7 @@ public:
   }
 
   long APELocation;
-  unsigned int APESize;
+  long APESize;
 
   long ID3v1Location;
 
@@ -174,7 +174,7 @@ bool WavPack::File::save()
     insert(data, d->APELocation, d->APESize);
 
     if(d->ID3v1Location >= 0)
-      d->ID3v1Location += (data.size() - d->APESize);
+      d->ID3v1Location += (static_cast<long>(data.size()) - d->APESize);
 
     d->APESize = data.size();
   }