diff --git a/proc/namespace.c b/proc/namespace.c
index cd4f47d5..59079dab 100644
--- a/proc/namespace.c
+++ b/proc/namespace.c
@@ -103,7 +103,7 @@ PROCPS_EXPORT int procps_ns_read_pid(
     for (i=0; i < PROCPS_NS_COUNT; i++) {
         snprintf(path, NSPATHLEN, "/proc/%d/ns/%s", pid, ns_names[i]);
         if (0 == stat(path, &st))
-            nsp->ns[i] = (long)st.st_ino;
+            nsp->ns[i] = (unsigned long)st.st_ino;
         else
             nsp->ns[i] = 0;
     }
diff --git a/proc/namespace.h b/proc/namespace.h
index 2aaea5c0..2885d8d5 100644
--- a/proc/namespace.h
+++ b/proc/namespace.h
@@ -36,7 +36,7 @@ enum namespace_type {
 };
 
 struct procps_namespaces {
-    long ns[PROCPS_NS_COUNT];
+    unsigned long ns[PROCPS_NS_COUNT];
 };
 
 const char *procps_ns_get_name(const int id);