diff --git a/tccgen.c b/tccgen.c
index cb9765c..35d5aaa 100644
--- a/tccgen.c
+++ b/tccgen.c
@@ -5146,7 +5146,7 @@ static void decl_initializer_alloc(CType *type, AttributeDef *ad, int r,
        literals). It also simplifies local
        initializers handling */
     tok_str_new(&init_str);
-    if (size < 0 || flexible_array) {
+    if (size < 0 || (flexible_array && has_init)) {
         if (!has_init) 
             error("unknown type size");
         /* get all init string */
diff --git a/tests/tcctest.c b/tests/tcctest.c
index 57459bb..629bcaa 100644
--- a/tests/tcctest.c
+++ b/tests/tcctest.c
@@ -1301,6 +1301,8 @@ struct complexinit2 {
 	int b[];
 };
 
+struct complexinit2 cix20;
+
 struct complexinit2 cix21 = {
 	.a = 3000,
 	.b = { 3001, 3002, 3003 }
@@ -1410,7 +1412,7 @@ void init_test(void)
 	cix[0].b[1].a, cix[0].b[1].b,
 	cix[0].b[2].a, cix[0].b[2].b);
     printf("cix2: %d %d\n", cix21.b[2], cix22.b[5]);
-    printf("sizeof cix21 %d, sizeof cix22 %d\n", sizeof cix21, sizeof cix22);
+    printf("sizeof cix20 %d, cix21 %d, sizeof cix22 %d\n", sizeof cix20, sizeof cix21, sizeof cix22);
 }