diff --git a/src/physfs_internal.h b/src/physfs_internal.h
index b3139ad..f33551a 100644
--- a/src/physfs_internal.h
+++ b/src/physfs_internal.h
@@ -1176,8 +1176,7 @@ int __PHYSFS_platformSeek(void *opaque, PHYSFS_uint64 pos);
  *
  * Not all file types can "tell"; this is to be expected by the caller.
  *
- * On error, call __PHYSFS_setError() and return zero. On success, return
- *  a non-zero value.
+ * On error, call __PHYSFS_setError() and return -1. On success, return >= 0.
  */
 PHYSFS_sint64 __PHYSFS_platformTell(void *opaque);
 
diff --git a/src/platform_pocketpc.c b/src/platform_pocketpc.c
index 7d8607c..81f91c2 100644
--- a/src/platform_pocketpc.c
+++ b/src/platform_pocketpc.c
@@ -409,7 +409,7 @@ PHYSFS_sint64 __PHYSFS_platformTell(void *opaque)
     LowPos = SetFilePointer(Handle, 0, &HighPos, FILE_CURRENT);
     if ((LowPos == INVALID_SET_FILE_POINTER) && (GetLastError() != NO_ERROR))
     {
-        BAIL_MACRO(win32strerror(), 0);
+        BAIL_MACRO(win32strerror(), -1);
     } /* if */
     else
     {
diff --git a/src/platform_windows.c b/src/platform_windows.c
index d151290..aa25690 100644
--- a/src/platform_windows.c
+++ b/src/platform_windows.c
@@ -1051,7 +1051,7 @@ PHYSFS_sint64 __PHYSFS_platformTell(void *opaque)
     if ( (LowPos == PHYSFS_INVALID_SET_FILE_POINTER) &&
          (GetLastError() != NO_ERROR) )
     {
-        BAIL_MACRO(winApiStrError(), 0);
+        BAIL_MACRO(winApiStrError(), -1);
     } /* if */
     else
     {