diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 5b03b9a..c7774fa 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -5157,9 +5157,10 @@ static inline void add_to_key(char *compound_key, void *key,
 		/* ensure NULL-termination */
 		if (size > key_field->size - 1)
 			size = key_field->size - 1;
-	}
 
-	memcpy(compound_key + key_field->offset, key, size);
+		strncpy(compound_key + key_field->offset, (char *)key, size);
+	} else
+		memcpy(compound_key + key_field->offset, key, size);
 }
 
 static void