diff --git a/cgdoom/i_system.c b/cgdoom/i_system.c
index e79a3c8..b747c00 100644
--- a/cgdoom/i_system.c
+++ b/cgdoom/i_system.c
@@ -69,9 +69,7 @@ byte* I_ZoneBase (int*	size, int i)
 
 byte *I_ScreenBase(int screen)
 {
-    if (screen == 0)
-        return malloc(320 * 200);
-    if (screen == 1)
+    if (screen == 0 || screen == 1 || screen == 2 || screen == 3)
         return malloc(320 * 200);
     if (screen == 4)
         return malloc(320 * 32);
diff --git a/cgdoom/p_setup.c b/cgdoom/p_setup.c
index 0692473..37e7791 100644
--- a/cgdoom/p_setup.c
+++ b/cgdoom/p_setup.c
@@ -662,7 +662,7 @@ void P_GroupLines (void)
   }
 
   // build line tables for each sector	
-  linebuffer = (line_t **)Z_Malloc (total*4, PU_LEVEL, 0);
+  linebuffer = (line_t **)Z_Malloc (total*sizeof(void *), PU_LEVEL, 0);
   sector = sectors;
   for (i=0 ; i<numsectors ; i++, sector++)
   {
diff --git a/cgdoom/z_zone.c b/cgdoom/z_zone.c
index 702ef80..d323e59 100644
--- a/cgdoom/z_zone.c
+++ b/cgdoom/z_zone.c
@@ -236,7 +236,7 @@ void* Z_Malloc( int size,  int  tag,  void* user )
   memblock_t* newblock;
   memblock_t* base;
 
-  size = (size + 3) & ~3;
+  size = (size + (sizeof(void *)-1)) & ~(sizeof(void *)-1);
 
   // scan through the block list,
   // looking for the first free block