diff --git a/generate4.xml b/generate4.xml
index 245a24a..ce8f1b5 100644
--- a/generate4.xml
+++ b/generate4.xml
@@ -272,6 +272,10 @@
 
     <package library="bitcoin-system" description="Bitcoin Cross-Platform C++ Development Toolkit" url="https://github.com/libbitcoin/libbitcoin-system" >
       <flag value="@icu@" />
+      <flag value="@avx2@" />
+      <flag value="@avx512@" />
+      <flag value="@shani@" />
+      <flag value="@sse4@" />
     </package>
 
     <configure>
diff --git a/templates/gsl.CMakeLists.txt b/templates/gsl.CMakeLists.txt
index 89aeb7e..c72b856 100644
--- a/templates/gsl.CMakeLists.txt
+++ b/templates/gsl.CMakeLists.txt
@@ -1144,6 +1144,7 @@ $(my.indent)endif()
 .
 $(my.indent)if ( $(my.define_prefix)$(my.compound.name:upper) )
     $(my.indent)add_compile_definitions( $(my.define_prefix)$(my.compound.name:upper) )
+    $(my.indent)set( $(my.compound.name:lower) "-D$(my.compound.type:upper)_$(my.compound.name:upper)" )
 $(my.indent)else()
     $(my.indent)message( FATAL_ERROR "Failed to enable $(my.define_prefix)$(my.compound.name:upper)" )
 $(my.indent)endif()
diff --git a/templates/gsl.configure.ac b/templates/gsl.configure.ac
index 52e0db2..ff7aced 100644
--- a/templates/gsl.configure.ac
+++ b/templates/gsl.configure.ac
@@ -1032,8 +1032,9 @@ AS_IF([test x${$(get_option_symbol(my.option))} != "xno"],
 .   else
 AX_CHECK_COMPILE_FLAG([$(my.flags)],
 .   endif
-    $(my.indent)[CXXFLAGS="$CXXFLAGS $(my.flags)";
-    $(my.indent) AC_DEFINE([$(my.compound.type:upper)_$(my.compound.name:upper)])],
+    $(my.indent)[AC_DEFINE([$(my.compound.type:upper)_$(my.compound.name:upper)])
+    $(my.indent) CXXFLAGS="$CXXFLAGS $(my.flags)";
+    $(my.indent) AC_SUBST([$(my.compound.name:lower)], [-D$(my.compound.type:upper)_$(my.compound.name:upper)])],
     $(my.indent)[AC_MSG_ERROR([$(my.flags) not supported.])],
 .   if defined(my.compound->program)
 .       define my.prog_indent = "    $(my.indent)"