diff --git a/contrib/guix/libexec/build_linux.sh b/contrib/guix/libexec/build_linux.sh
index 492890ecc1c..f1b25b52e55 100755
--- a/contrib/guix/libexec/build_linux.sh
+++ b/contrib/guix/libexec/build_linux.sh
@@ -65,6 +65,12 @@ esac
 # LDFLAGS
 HOST_LDFLAGS="-Wl,--as-needed -Wl,--dynamic-linker=$(glibc_dynamic_linker "$HOST") -Wl,-O2"
 
+# Use LINK_WARNING_AS_ERROR when using CMake 4.x
+case "$HOST" in
+    riscv64-linux-gnu) ;; # https://github.com/boostorg/test/issues/345
+    *) HOST_LDFLAGS="${HOST_LDFLAGS} -Wl,--fatal-warnings" ;;
+esac
+
 mkdir -p "$DISTSRC"
 (
     cd "$DISTSRC"
diff --git a/contrib/guix/libexec/build_win.sh b/contrib/guix/libexec/build_win.sh
index ce1f7fd4d03..de9870f879e 100755
--- a/contrib/guix/libexec/build_win.sh
+++ b/contrib/guix/libexec/build_win.sh
@@ -54,7 +54,7 @@ HOST_CFLAGS+=" -fno-ident"
 HOST_CXXFLAGS="$HOST_CFLAGS"
 
 # LDFLAGS
-HOST_LDFLAGS="-Wl,--no-insert-timestamp"
+HOST_LDFLAGS="-Wl,--no-insert-timestamp -Wl,--fatal-warnings"
 
 mkdir -p "$DISTSRC"
 (
diff --git a/contrib/guix/libexec/build_win_gui.sh b/contrib/guix/libexec/build_win_gui.sh
index 94f21166392..ec5048d84ea 100755
--- a/contrib/guix/libexec/build_win_gui.sh
+++ b/contrib/guix/libexec/build_win_gui.sh
@@ -53,7 +53,7 @@ HOST_CFLAGS+=" -fno-ident"
 HOST_CXXFLAGS="$HOST_CFLAGS"
 
 # LDFLAGS
-HOST_LDFLAGS="-Wl,--no-insert-timestamp"
+HOST_LDFLAGS="-Wl,--no-insert-timestamp -Wl,--fatal-warnings"
 
 mkdir -p "$DISTSRC"
 (