diff --git a/src/vt/group/collective/group_info_collective.cc b/src/vt/group/collective/group_info_collective.cc
index 7c7075eb67..2ded4cc4ef 100644
--- a/src/vt/group/collective/group_info_collective.cc
+++ b/src/vt/group/collective/group_info_collective.cc
@@ -696,11 +696,12 @@ void InfoColl::finalize() {
   if (in_phase_two_ && send_down_finished_ == send_down_) {
 
     if (!vt_check_enabled(production_build)) {
-      char buf[256];
+      constexpr int max_buffer_length = 256;
+      char buf[max_buffer_length];
       buf[0] = '\0';
       int cur = 0;
       for (auto&& elm : collective_->span_children_) {
-        cur += sprintf(buf + cur, "%d,", elm);
+        cur += snprintf(buf + cur, max_buffer_length - cur, "%d,", elm);
       }
 
       auto const& num_children = collective_->span_children_.size();
diff --git a/src/vt/runtime/runtime.cc b/src/vt/runtime/runtime.cc
index 7d73260004..51ace6b1c9 100644
--- a/src/vt/runtime/runtime.cc
+++ b/src/vt/runtime/runtime.cc
@@ -249,9 +249,10 @@ bool Runtime::hasSchedRun() const {
 
 void Runtime::pauseForDebugger() {
   if (theConfig()->vt_pause) {
-    char node_str[256];
+    constexpr int max_buffer_length = 256;
+    char node_str[max_buffer_length];
     auto node = vt::theContext() ? vt::theContext()->getNode() : -1;
-    sprintf(node_str, "prog-%d.pid", node);
+    snprintf(node_str, max_buffer_length, "prog-%d.pid", node);
     auto const pid = getpid();
     FILE* f = fopen(node_str, "w+");
     fprintf(f, "%d", pid);