diff --git a/ps/output.c b/ps/output.c
index 62b23c19..8c6a5289 100644
--- a/ps/output.c
+++ b/ps/output.c
@@ -147,8 +147,8 @@ static int sr_ ## NAME (const proc_t* P, const proc_t* Q) { \
 
 #define CMP_NS(NAME, ID) \
 static int sr_ ## NAME (const proc_t* P, const proc_t* Q) { \
-    if (P->ns[ID] < Q->ns[ID]) return -1; \
-    if (P->ns[ID] > Q->ns[ID]) return  1; \
+    if ((unsigned long)P->ns[ID] < (unsigned long)Q->ns[ID]) return -1; \
+    if ((unsigned long)P->ns[ID] > (unsigned long)Q->ns[ID]) return  1; \
     return 0; \
 }
 
@@ -1236,7 +1236,7 @@ static int pr_sd_slice(char *restrict const outbuf, const proc_t *restrict const
 #define _pr_ns(NAME, ID)\
 static int pr_##NAME(char *restrict const outbuf, const proc_t *restrict const pp) {\
   if (pp->ns[ID])\
-    return snprintf(outbuf, COLWID, "%li", pp->ns[ID]);\
+    return snprintf(outbuf, COLWID, "%lu", (unsigned long)pp->ns[ID]);\
   else\
     return snprintf(outbuf, COLWID, "-");\
 }