diff --git a/stralloc.h b/stralloc.h
index 85e6a0e..4152ac9 100644
--- a/stralloc.h
+++ b/stralloc.h
@@ -67,7 +67,7 @@ void stralloc_zero(stralloc* sa);
 int stralloc_catm_internal(stralloc* sa,...);
 
 #define stralloc_catm(sa,...) stralloc_catm_internal(sa,__VA_ARGS__,(char*)0)
-#define stralloc_copym(sa,...) (stralloc_zero(sa) && stralloc_catm_internal(sa,__VA_ARGS__,(char*)0))
+#define stralloc_copym(sa,...) (stralloc_zero(sa), stralloc_catm_internal(sa,__VA_ARGS__,(char*)0))
 
 /* stralloc_cat is analogous to stralloc_copy */
 int stralloc_cat(stralloc* sa,stralloc* in);
diff --git a/t.c b/t.c
index 17185b1..7930128 100644
--- a/t.c
+++ b/t.c
@@ -318,7 +318,7 @@ int main(int argc,char* argv[]) {
   rdtscl(c);
   printf("%lu %lu\n",b-a,c-b);
 #endif
-#if 1
+#if 0
   size_t size;
   char* buf=mmap_read(argv[1],&size);
   if (buf) {
@@ -333,6 +333,7 @@ int main(int argc,char* argv[]) {
   printf("%d %d\n",strcmp("foo","bar"),str_diff("foo","bar"));
   printf("%d %d\n",strcmp("foo","üar"),str_diff("foo","üar"));
 #endif
+#if 0
   {
     int16 a;
     int32 b;
@@ -348,6 +349,9 @@ int main(int argc,char* argv[]) {
     assert(imult64(0x4000000000000000ll,2,&c)==0);
     assert(imult64(0x3fffffffffffffffll,2,&c)==1 && c==0x7ffffffffffffffell);
   }
+#endif
+  stralloc a;
+  printf("%d\n",stralloc_copym(&a,"fnord",", ","foo"));
 
   return 0;
 }