diff --git a/src/p_setup.c b/src/p_setup.c
index cc46c6d64..61f5fe000 100644
--- a/src/p_setup.c
+++ b/src/p_setup.c
@@ -1055,7 +1055,7 @@ static void P_LoadLinedefs(UINT8 *data)
 		ld->special = SHORT(mld->special);
 		ld->tag = SHORT(mld->tag);
 		memset(ld->args, 0, NUMLINEARGS*sizeof(*ld->args));
-		memset(ld->stringargs, (int)NULL, NUMLINESTRINGARGS*sizeof(*ld->stringargs));
+		memset(ld->stringargs, 0x00, NUMLINESTRINGARGS*sizeof(*ld->stringargs));
 		P_SetLinedefV1(i, SHORT(mld->v1));
 		P_SetLinedefV2(i, SHORT(mld->v2));
 
@@ -1648,7 +1648,7 @@ static void P_LoadTextmap(void)
 		ld->special = 0;
 		ld->tag = 0;
 		memset(ld->args, 0, NUMLINEARGS*sizeof(*ld->args));
-		memset(ld->stringargs, (int)NULL, NUMLINESTRINGARGS*sizeof(*ld->stringargs));
+		memset(ld->stringargs, 0x00, NUMLINESTRINGARGS*sizeof(*ld->stringargs));
 		ld->sidenum[0] = 0xffff;
 		ld->sidenum[1] = 0xffff;