diff --git a/cmake-config b/cmake-config
index 2ae29736b1..8575bf104e 100755
--- a/cmake-config
+++ b/cmake-config
@@ -164,7 +164,7 @@ then
       CC=icx
       FC=ifx
       CFLAGS="-Wall -Wunused"
-      CXXFLAGS="-Wall -Wextra  -Wunused"
+      CXXFLAGS="-Wall -Wextra  -Wunused -DFMT_HEADER_ONLY"
   fi
 
   # When building:  "scan-build make -j8"