diff --git a/lib/libalias/alias_util.c b/lib/libalias/alias_util.c
index fe076531201..cb948c3385f 100644
--- a/lib/libalias/alias_util.c
+++ b/lib/libalias/alias_util.c
@@ -43,7 +43,8 @@ PacketAliasInternetChecksum(u_short *ptr, int nbytes)
     if (nbytes == 1)
     {
         oddbyte = 0;
-        *((u_char *) &oddbyte) = *(u_char *) ptr;
+        ((u_char *) &oddbyte)[0] = *(u_char *) ptr;
+        ((u_char *) &oddbyte)[1] = 0;
         sum += oddbyte;
     }
     sum = (sum >> 16) + (sum & 0xffff);
@@ -84,7 +85,8 @@ TcpChecksum(struct ip *pip)
     if (nbytes == 1)
     {
         oddbyte = 0;
-        *((u_char *) &oddbyte) = *(u_char *) ptr;
+        ((u_char *) &oddbyte)[0] = *(u_char *) ptr;
+        ((u_char *) &oddbyte)[1] = 0;
         sum += oddbyte;
     }
 
diff --git a/sys/netinet/libalias/alias_util.c b/sys/netinet/libalias/alias_util.c
index fe076531201..cb948c3385f 100644
--- a/sys/netinet/libalias/alias_util.c
+++ b/sys/netinet/libalias/alias_util.c
@@ -43,7 +43,8 @@ PacketAliasInternetChecksum(u_short *ptr, int nbytes)
     if (nbytes == 1)
     {
         oddbyte = 0;
-        *((u_char *) &oddbyte) = *(u_char *) ptr;
+        ((u_char *) &oddbyte)[0] = *(u_char *) ptr;
+        ((u_char *) &oddbyte)[1] = 0;
         sum += oddbyte;
     }
     sum = (sum >> 16) + (sum & 0xffff);
@@ -84,7 +85,8 @@ TcpChecksum(struct ip *pip)
     if (nbytes == 1)
     {
         oddbyte = 0;
-        *((u_char *) &oddbyte) = *(u_char *) ptr;
+        ((u_char *) &oddbyte)[0] = *(u_char *) ptr;
+        ((u_char *) &oddbyte)[1] = 0;
         sum += oddbyte;
     }