diff --git a/src/VM/VM.c b/src/VM/VM.c
index 1c9105e..96763f2 100644
--- a/src/VM/VM.c
+++ b/src/VM/VM.c
@@ -77,7 +77,9 @@ i32 VM_boot(VM* vm){
 
 bool VM_dataRead(VM* vm, void* dst, size_t pos, size_t size){
     if(pos + size >= vm->data_size){
-        VM_setError(vm, "can't read %lli bytes from 0x%x, because only %lli are avaliable",
+        VM_setError(vm, 
+            "can't read " IFWIN("%lli", "%li") " bytes from 0x%x, because only "
+                IFWIN("%lli", "%li") " are avaliable",
             size, (u32)pos, vm->data_size - size);
         return false;
     }
diff --git a/src/cstr.c b/src/cstr.c
index af6aac1..0552230 100644
--- a/src/cstr.c
+++ b/src/cstr.c
@@ -43,7 +43,7 @@ char* NULLABLE(sprintf_malloc)(size_t buffer_size, cstr format, ...){
 
 char* NULLABLE(vsprintf_malloc)(size_t buffer_size, cstr format, va_list argv){
     char* buf = malloc(buffer_size);
-    int r = vsprintf_s(buf, buffer_size, format, argv);
+    int r = vsprintf(buf, format, argv);
     if(r < 0){
         free(buf);
         return NULL;
diff --git a/src/std.h b/src/std.h
index a5e4b16..5a22ad4 100644
--- a/src/std.h
+++ b/src/std.h
@@ -26,6 +26,12 @@ typedef u8 bool;
 
 typedef const char* cstr;
 
+#if defined(_WIN64) || defined(_WIN32)
+    #define IFWIN(YES, NO) YES
+#else
+    #define IFWIN(YES, NO) NO
+#endif
+
 #define ARRAY_SIZE(A) (sizeof(A)/sizeof(A[0]))
 #define ALIGN_TO(_SIZE,_ALIGN)        (((_SIZE) + ((_ALIGN) - 1)) & ~((_ALIGN) - 1))
 
diff --git a/src/string/StringBuilder.c b/src/string/StringBuilder.c
index 16d11cc..5f27fd0 100644
--- a/src/string/StringBuilder.c
+++ b/src/string/StringBuilder.c
@@ -36,18 +36,18 @@ void StringBuilder_append_cstr(StringBuilder* b, char* s){
 
 void StringBuilder_append_i64(StringBuilder* b, i64 n){
     char buf[32];
-    sprintf_s(buf, sizeof(buf), "%llu", n);
+    sprintf(buf, IFWIN("%lli", "%li"), n);
     StringBuilder_append_cstr(b, buf);
 }
 
 void StringBuilder_append_u64(StringBuilder* b, u64 n){
     char buf[32];
-    sprintf_s(buf, sizeof(buf), "%llu", n);
+    sprintf(buf, IFWIN("%llu", "%lu"), n);
     StringBuilder_append_cstr(b, buf);
 }
 
 void StringBuilder_append_f64(StringBuilder* b, f64 n){
     char buf[32];
-    sprintf_s(buf, sizeof(buf), "%lf", n);
+    sprintf(buf, "%lf", n);
     StringBuilder_append_cstr(b, buf);
 }