diff --git a/src/util/strbuf.c b/src/util/strbuf.c
index 27dc95a1..23517586 100644
--- a/src/util/strbuf.c
+++ b/src/util/strbuf.c
@@ -66,7 +66,11 @@ int strbuf_vprintf(StringBuffer *strbuf, const char *format, va_list args) {
 	return size_required;
 }
 
-int strbuf_ncat(StringBuffer *strbuf, size_t datasize, const char data[datasize]) {
+int strbuf_ncat(StringBuffer *strbuf, size_t datasize, const char data[]) {
+	if(UNLIKELY(!datasize)) {
+		return 0;
+	}
+
 	assert(datasize < INT32_MAX);
 	strbuf_reserve(strbuf, datasize + 1);
 	assert_nolog(strbuf_size_available(strbuf) >= datasize + 1);
diff --git a/src/util/strbuf.h b/src/util/strbuf.h
index e6ca2631..536e7a23 100644
--- a/src/util/strbuf.h
+++ b/src/util/strbuf.h
@@ -29,7 +29,7 @@ void strbuf_clear(StringBuffer *strbuf)
 void strbuf_free(StringBuffer *strbuf)
 	attr_nonnull(1);
 
-int strbuf_ncat(StringBuffer *strbuf, size_t datasize, const char data[datasize])
+int strbuf_ncat(StringBuffer *strbuf, size_t datasize, const char data[])
 	attr_nonnull(1, 3);
 
 INLINE int strbuf_cat(StringBuffer *strbuf, const char *str) {