diff --git a/package/kmsxx/Config.in b/package/kmsxx/Config.in
index 6e4d1e61a1..fa327ba18d 100644
--- a/package/kmsxx/Config.in
+++ b/package/kmsxx/Config.in
@@ -4,6 +4,7 @@ config BR2_PACKAGE_KMSXX
 	depends on BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_11 # linux/dma-buf.h
 	depends on BR2_INSTALL_LIBSTDCPP
 	depends on BR2_TOOLCHAIN_HAS_THREADS # libdrm
+	depends on BR2_USE_WCHAR # fmt
 	select BR2_PACKAGE_FMT
 	select BR2_PACKAGE_LIBDRM
 	help
@@ -22,6 +23,7 @@ config BR2_PACKAGE_KMSXX_INSTALL_TESTS
 
 endif
 
-comment "kms++ needs a toolchain w/ threads, C++, gcc >= 4.8, headers >= 4.11"
+comment "kms++ needs a toolchain w/ threads, C++, gcc >= 4.8, headers >= 4.11, wchar"
 	depends on !BR2_TOOLCHAIN_HAS_THREADS || !BR2_INSTALL_LIBSTDCPP || \
-		!BR2_TOOLCHAIN_GCC_AT_LEAST_4_8 || !BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_11
+		!BR2_TOOLCHAIN_GCC_AT_LEAST_4_8 || !BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_11 \
+		|| !BR2_USE_WCHAR