diff --git a/libtcc.c b/libtcc.c
index d63b86f..63b25ce 100644
--- a/libtcc.c
+++ b/libtcc.c
@@ -1146,9 +1146,12 @@ LIBTCCAPI TCCState *tcc_new(void)
 #if defined TCC_TARGET_PE && defined TCC_TARGET_X86_64
     tcc_define_symbol(s, "__SIZE_TYPE__", "unsigned long long");
     tcc_define_symbol(s, "__PTRDIFF_TYPE__", "long long");
-#else
+#elif defined(TCC_TARGET_X86_64) || defined(TCC_TARGET_ARM64)
     tcc_define_symbol(s, "__SIZE_TYPE__", "unsigned long");
     tcc_define_symbol(s, "__PTRDIFF_TYPE__", "long");
+#else
+    tcc_define_symbol(s, "__SIZE_TYPE__", "unsigned int");
+    tcc_define_symbol(s, "__PTRDIFF_TYPE__", "int");
 #endif
 
 #ifdef TCC_TARGET_PE