diff --git a/pkgs/os-specific/linux/dietlibc/builder.sh b/pkgs/os-specific/linux/dietlibc/builder.sh
index ab20c8ea1b5..0f1dbf534c5 100644
--- a/pkgs/os-specific/linux/dietlibc/builder.sh
+++ b/pkgs/os-specific/linux/dietlibc/builder.sh
@@ -15,6 +15,10 @@ postInstall() {
 
     # Copy <sys/user.h> from Glibc; binutils wants it.
     cp $glibc/include/sys/user.h $out/include/sys/
+
+    # This header is bogus: it contains declarations that aren't
+    # defined anywhere.
+    rm $out/include/wchar.h
 }
 
 genericBuild