diff --git a/src/api.c b/src/api.c
index 467d520..65d1a07 100644
--- a/src/api.c
+++ b/src/api.c
@@ -11,14 +11,18 @@ void api_put() {
     int mode = state->STACK[state->STACK_IDX--]; // 1 for char, 2 for num
     if (mode != 1 && mode != 2) return;
 
+    FILE *f = fstream;
+    if (f == stderr)
+	f = stdout;
+    
     if (mode == 1) {
 	char c = state->STACK[state->STACK_IDX--];
 	if (c == '\0') c = ' ';
 
-	printf("%c", c); //using printf and not write because of the buffer
+	fprintf(f, "%c", c); //using printf and not write because of the buffer
     }
     else {
-	printf("%d", state->STACK[state->STACK_IDX--]);
+	fprintf(f, "%d", state->STACK[state->STACK_IDX--]);
     }
 }