diff --git a/src/common/FFstrbuf.h b/src/common/FFstrbuf.h
index d84ed3506..0f4f405a6 100644
--- a/src/common/FFstrbuf.h
+++ b/src/common/FFstrbuf.h
@@ -629,4 +629,4 @@ static inline void ffStrbufPutTo(const FFstrbuf* strbuf, FILE* file) {
 bool ffStrbufDecodeHexEscapeSequences(FFstrbuf* strbuf);
 
 #define FF_STRBUF_AUTO_DESTROY [[gnu::cleanup(ffStrbufDestroy)]] FFstrbuf
-#define FF_STRBUF_STATIC(str) { .allocated = 0, .length = (uint32_t) ARRAY_SIZE(str) - 1, .chars = str }
+#define FF_STRBUF_STATIC(str) { .allocated = 0, .length = (uint32_t) sizeof(str) - 1, .chars = str }