diff --git a/configure b/configure
index b9ffcd27e..416cf307c 100755
--- a/configure
+++ b/configure
@@ -6711,7 +6711,7 @@ if ac_fn_cxx_try_compile "$LINENO"
 then :
   { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
 printf "%s\n" "no" >&6; }
-                                            QBT_ADD_CONFIG="$QBT_ADD_CONFIG c++17"
+                                            QBT_ADD_CONFIG="$QBT_ADD_CONFIG c++1z"
                                             { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: C++17 mode is now force enabled. The C++ mode should match the mode that other libraries were built with, otherwise you'll likely get linking errors." >&5
 printf "%s\n" "$as_me: WARNING: C++17 mode is now force enabled. The C++ mode should match the mode that other libraries were built with, otherwise you'll likely get linking errors." >&2;}
 else $as_nop
diff --git a/configure.ac b/configure.ac
index 95e95cdf8..62840c6bc 100644
--- a/configure.ac
+++ b/configure.ac
@@ -216,7 +216,7 @@ AS_IF([test "x$QBT_CXX17_FOUND" = "xno"],
                          CXXFLAGS="-std=c++17 $TMP_CXXFLAGS"
                          AC_COMPILE_IFELSE([DETECT_CPP17_PROGRAM()],
                                            [AC_MSG_RESULT([no])
-                                            QBT_ADD_CONFIG="$QBT_ADD_CONFIG c++17"
+                                            QBT_ADD_CONFIG="$QBT_ADD_CONFIG c++1z"
                                             AC_MSG_WARN([C++17 mode is now force enabled. The C++ mode should match the mode that other libraries were built with, otherwise you'll likely get linking errors.])],
                                            [AC_MSG_RESULT([yes])
                                             AC_MSG_ERROR([The compiler supports C++17 but the user or a dependency has explicitly enabled a lower mode.])])],