diff --git a/config.h.cmake.in b/config.h.cmake.in
index e33d9100f..4bf340f7e 100644
--- a/config.h.cmake.in
+++ b/config.h.cmake.in
@@ -210,7 +210,7 @@ are set when opening a binary file on Windows. */
 #cmakedefine HAVE_FILE_LENGTH_I64 @HAVE_FILE_LENGTH_I64@
 
 /* Define whether char is signed by default. */
-#cmakedefine __CHAR_UNSIGNED__
+//#cmakedefine __CHAR_UNSIGNED__
 
 /* The size of `void*` as computed by sizeof. */
 #cmakedefine SIZEOF_VOIDSTAR @SIZEOF_VOIDSTAR@