diff --git a/v2.5/generators/nlojet++/configure.ac b/v2.5/generators/nlojet++/configure.ac
index 67582390207e375633bc3576eb1359695bb713f1..6c6819506c0dc8fc77fe79bd8fbaef6b1b02416a 100644
--- a/v2.5/generators/nlojet++/configure.ac
+++ b/v2.5/generators/nlojet++/configure.ac
@@ -58,10 +58,10 @@ AM_CONDITIONAL([HAVE_LIBZ],[test "x$HAVE_LIBZ" == "xtrue"])
 AC_HEADER_STDBOOL
 AC_C_INLINE
 
-# Require full C++11 functionality, which has been supported by gcc since version 4.8.1
+# Require full C++17 functionality, which has been supported by gcc since version 11
 # If the following macro is not found, you might want to install the autoconf-archive
 # package and repeat the 'autoreconf -i' step.
-AX_CXX_COMPILE_STDCXX_11
+AX_CXX_COMPILE_STDCXX_17
 
 # Checks for library functions.
 AC_FUNC_ERROR_AT_LINE
diff --git a/v2.5/toolkit/configure.ac b/v2.5/toolkit/configure.ac
index c84e754c830c08cf3272f6ffbd62b7e1a37f7f24..70994ebaca2f8fa691b9cb513b86ff3af1a63526 100644
--- a/v2.5/toolkit/configure.ac
+++ b/v2.5/toolkit/configure.ac
@@ -57,7 +57,7 @@ AM_CONDITIONAL([HAVE_LIBZ],[test "x$HAVE_LIBZ" == "xtrue"])
 AC_HEADER_STDBOOL
 AC_C_INLINE
 
-# Require full C++11 functionality, which has been supported by gcc since version 4.8.1
+# Require full C++17 functionality, which has been supported by gcc since version 11
 # If the following macro is not found, you might want to install the autoconf-archive
 # package and repeat the 'autoreconf -i' step.
 AX_CXX_COMPILE_STDCXX_17