diff --git a/base/HidlSupport.cpp b/base/HidlSupport.cpp
index f857281..aec3fed 100644
--- a/base/HidlSupport.cpp
+++ b/base/HidlSupport.cpp
@@ -217,7 +217,7 @@
 void hidl_string::copyFrom(const char *data, size_t size) {
     // assume my resources are freed.
 
-    if (size > UINT32_MAX) {
+    if (size >= UINT32_MAX) {
         LOG(FATAL) << "string size can't exceed 2^32 bytes: " << size;
     }
     char *buf = (char *)malloc(size + 1);