https://bugs.gentoo.org/832733
--- a/configure.ac
+++ b/configure.ac
@@ -55,7 +55,7 @@
 AC_PROG_LIBTOOL
 AC_SUBST(LIBTOOL_DEPS)
 
-LIB_PLUGINS = ''
+LIB_PLUGINS=''
 
 # Add configure option --enable-maintainer-mode which enables dependency
 # checking and generation useful to package maintainers.  This is made an
@@ -149,7 +149,7 @@
             [
                 with_fastfloat='no'
             ])
-if test "$with_fastfloat" == "yes"
+if test "$with_fastfloat" = "yes"
 then
             LIB_PLUGINS="$LIB_PLUGINS -llcms2_fast_float"
 fi