diff --git a/poet/CMakeLists.txt b/poet/CMakeLists.txt
index f2125ba1..f6f4b0d6 100644
--- a/poet/CMakeLists.txt
+++ b/poet/CMakeLists.txt
@@ -9,4 +9,4 @@ target_include_directories(IPhreeqcPOET PUBLIC
     PRIVATE src)
 
 # Set C++23 standard
-target_compile_features(IPhreeqcPOET PUBLIC cxx_std_23)
\ No newline at end of file
+target_compile_features(IPhreeqcPOET PUBLIC cxx_std_20)
\ No newline at end of file