diff --git a/src/p_mach.cpp b/src/p_mach.cpp
index 29b21ec8..dfb2b616 100644
--- a/src/p_mach.cpp
+++ b/src/p_mach.cpp
@@ -342,7 +342,7 @@ PackMachPPC32::canPack()
     unsigned char *ptr = (unsigned char *)rawmseg;
     for (unsigned j= 0; j < mhdri.ncmds; ++j) {
         msegcmd[j] = *(Mach_segment_command *)ptr;
-        ptr += ((Mach_segment_command *)ptr)->cmdsize;
+        ptr += (unsigned) ((Mach_segment_command *)ptr)->cmdsize;
     }