Integer multiplication truncation

The following code executes as I would expect on gcc:

#include <inttypes.h>
#include <stdio.h>

int main(int argc, char **argv){
   uint16_t apa         = 10000;
   uint16_t kaka        = 7000;
   uint32_t mazarin;

   mazarin = apa*kaka;
   printf("%lu \n",mazarin);
   return 0;
}

I.e. it will print out the value 70000000. However, when I compile
this another compiler the result is truncated and I have to modify the
code to the following to make it run:

#include <inttypes.h>
#include <stdio.h>

int main(int argc, char **argv){
   uint16_t apa         = 10000;
   uint16_t kaka        = 7000;
   uint32_t mazarin;

   mazarin = (uint32_t)apa*kaka;
   printf("%lu \n",mazarin);
   return 0;
}


Could anybody explain this? Is this due to C99 improvements regarding
integer overflow? Is there any predefined macro one could use to
determine this special case?

(Note: The extended types in inttypes.h were added for the second
compiler.)


Regards
/Michael