diff --git a/tools/elf2nro.c b/tools/elf2nro.c
index f4e84ead..72e56ced 100644
--- a/tools/elf2nro.c
+++ b/tools/elf2nro.c
@@ -126,7 +126,7 @@ int main(int argc, char* argv[]) {
         
         // .bss is special
         if (i == 3) {
-            nro_hdr.bssSize = (phdr->p_memsz + 0xFFF) & ~0xFFF;
+            nro_hdr.bssSize = ((phdr->p_memsz - phdr->p_filesz) + 0xFFF) & ~0xFFF;
             break;
         }
 
diff --git a/tools/elf2nso.c b/tools/elf2nso.c
index 7ec34996..bf2ce3a5 100644
--- a/tools/elf2nso.c
+++ b/tools/elf2nso.c
@@ -127,9 +127,9 @@ int main(int argc, char* argv[]) {
         nso_hdr.Segments[i].DstOff = phdr->p_vaddr;
         nso_hdr.Segments[i].DecompSz = phdr->p_filesz;
 
-        // for .data segment this field contains total sz including bss
+        // for .data segment this field contains bss size
         if (i == 2)
-            nso_hdr.Segments[i].AlignOrTotalSz = phdr->p_memsz;
+            nso_hdr.Segments[i].AlignOrTotalSz = phdr->p_memsz - phdr->p_filesz;
         else
             nso_hdr.Segments[i].AlignOrTotalSz = 1;