diff --git a/libluna/src/Format.cpp b/libluna/src/Format.cpp
index 1754942c..3fed3ca0 100644
--- a/libluna/src/Format.cpp
+++ b/libluna/src/Format.cpp
@@ -503,15 +503,18 @@ usize vstring_format(char* buf, usize max, const char* format, va_list ap)
                        [](char c, void* arg) -> Result<void> {
                            StringFormatInfo* info_arg = (StringFormatInfo*)arg;
                            if (!info_arg->remaining) return {};
-                           *(info_arg->buffer) = c;
-                           info_arg->buffer++;
+                           if (info_arg->buffer)
+                           {
+                               *(info_arg->buffer) = c;
+                               info_arg->buffer++;
+                           }
                            info_arg->remaining--;
                            return {};
                        },
                        &info, ap)
                        .value();
 
-    *(info.buffer) = 0;
+    if (info.buffer) *(info.buffer) = 0;
 
     return result;
 }