diff --git a/proc/pids.c b/proc/pids.c
index 37a1e9f0..ff66cede 100644
--- a/proc/pids.c
+++ b/proc/pids.c
@@ -848,7 +848,7 @@ static inline void oldproc_close (
 
 static inline int oldproc_open (
         struct procps_pidsinfo *info,
-        int supp_flgs,
+        unsigned supp_flgs,
         ...)
 {
     va_list vl;
diff --git a/proc/readproc.c b/proc/readproc.c
index 7784ad93..9036f11c 100644
--- a/proc/readproc.c
+++ b/proc/readproc.c
@@ -1319,7 +1319,7 @@ end_procs:
 //////////////////////////////////////////////////////////////////////////////////
 
 // initiate a process table scan
-PROCTAB* openproc(int flags, ...) {
+PROCTAB* openproc(unsigned flags, ...) {
     va_list ap;
     struct stat sbuf;
     static int did_stat;
@@ -1401,7 +1401,7 @@ HIDDEN_ALIAS(readeither);
  * Free allocated memory with exit().  Access via tab[N]->member.  The pointer
  * list is NULL terminated.
  */
-proc_t** readproctab(int flags, ...) {
+proc_t** readproctab(unsigned flags, ...) {
     PROCTAB* PT = NULL;
     proc_t** tab = NULL;
     int n = 0;
diff --git a/proc/readproc.h b/proc/readproc.h
index 8d69a991..80924716 100644
--- a/proc/readproc.h
+++ b/proc/readproc.h
@@ -210,7 +210,7 @@ typedef struct PROCTAB {
 } PROCTAB;
 
 // Initialize a PROCTAB structure holding needed call-to-call persistent data
-extern PROCTAB* openproc(int flags, ... /* pid_t*|uid_t*|dev_t*|char* [, int n] */ );
+extern PROCTAB* openproc(unsigned flags, ... /* pid_t*|uid_t*|dev_t*|char* [, int n] */ );
 
 typedef struct proc_data_t {  // valued by: (else zero)
     proc_t **tab;             //     readproctab2, readproctab3
@@ -228,7 +228,7 @@ extern proc_data_t *readproctab3(int(*want_task)(proc_t *buf), PROCTAB *__restri
 // table subset satisfying the constraints of flags and the optional PID list.
 // Free allocated memory with exit().  Access via tab[N]->member.  The pointer
 // list is NULL terminated.
-extern proc_t** readproctab(int flags, ... /* same as openproc */ );
+extern proc_t** readproctab(unsigned flags, ... /* same as openproc */ );
 
 // Clean-up open files, etc from the openproc()
 extern void closeproc(PROCTAB* PT);