diff --git a/src/lj_ccall.c b/src/lj_ccall.c
index eb73604f..97dcc546 100644
--- a/src/lj_ccall.c
+++ b/src/lj_ccall.c
@@ -173,9 +173,10 @@
 
 #define CCALL_HANDLE_REGARG \
   if (isfp) {  /* Try to pass argument in FPRs. */ \
-    if (nfpr + n <= CCALL_NARG_FPR) { \
+    int n2 = ctype_isvector(d->info) ? 1 : n; \
+    if (nfpr + n2 <= CCALL_NARG_FPR) { \
       dp = &cc->fpr[nfpr]; \
-      nfpr += n; \
+      nfpr += n2; \
       goto done; \
     } \
   } else {  /* Try to pass argument in GPRs. */ \