diff --git a/libc/src/wchar/CMakeLists.txt b/libc/src/wchar/CMakeLists.txt
--- a/libc/src/wchar/CMakeLists.txt
+++ b/libc/src/wchar/CMakeLists.txt
@@ -6,5 +6,6 @@
   HDRS
     wctob.h
   DEPENDS 
+    libc.include.stdio
     libc.src.__support.wctype_utils
 )
diff --git a/libc/test/src/wchar/CMakeLists.txt b/libc/test/src/wchar/CMakeLists.txt
--- a/libc/test/src/wchar/CMakeLists.txt
+++ b/libc/test/src/wchar/CMakeLists.txt
@@ -7,6 +7,7 @@
   SRCS
     btowc_test.cpp
   DEPENDS
+    libc.include.stdio
     libc.src.wchar.btowc
 )