diff --git a/tools/build/cross-build/include/common/string.h b/tools/build/cross-build/include/common/string.h
index dd039d54583e..8a33f4d4ff19 100644
--- a/tools/build/cross-build/include/common/string.h
+++ b/tools/build/cross-build/include/common/string.h
@@ -38,7 +38,9 @@
 #pragma once
 
 /* Avoid incompatible opensolaris redeclarations (without _FORTIFY_SOURCE). */
+#undef HAVE_STRLCAT
 #define HAVE_STRLCAT 1
+#undef HAVE_STRLCPY
 #define HAVE_STRLCPY 1
 
 #include_next <string.h>