diff --git a/libc/system_properties/context_node.cpp b/libc/system_properties/context_node.cpp
index 5496b5a..d392c0a 100644
--- a/libc/system_properties/context_node.cpp
+++ b/libc/system_properties/context_node.cpp
@@ -51,7 +51,7 @@
 
   char filename[PROP_FILENAME_MAX];
   int len = async_safe_format_buffer(filename, sizeof(filename), "%s/%s", filename_, context_);
-  if (len < 0 || len > PROP_FILENAME_MAX) {
+  if (len < 0 || len >= PROP_FILENAME_MAX) {
     lock_.unlock();
     return false;
   }
@@ -86,7 +86,7 @@
 bool ContextNode::CheckAccess() {
   char filename[PROP_FILENAME_MAX];
   int len = async_safe_format_buffer(filename, sizeof(filename), "%s/%s", filename_, context_);
-  if (len < 0 || len > PROP_FILENAME_MAX) {
+  if (len < 0 || len >= PROP_FILENAME_MAX) {
     return false;
   }