diff --git a/aclocal.m4 b/aclocal.m4
index c02c1d109fcdb42e429ad5f9423f9449f8b5e097..91cdd40b136df066d1f37063653f4351d7b0225c 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -1976,7 +1976,7 @@ AC_DEFUN([GHC_CONVERT_OS],[
         $3="linux"
         ;;
       # As far as I'm aware, none of these have relevant variants
-      freebsd|netbsd|openbsd|dragonfly|hpux|linuxaout|kfreebsdgnu|freebsd2|solaris2|mingw32|darwin|gnu|nextstep2|nextstep3|sunos4|ultrix|haiku)
+      freebsd|netbsd|openbsd|dragonfly|hpux|linuxaout|kfreebsdgnu|freebsd2|mingw32|darwin|gnu|nextstep2|nextstep3|sunos4|ultrix|haiku)
         $3="$1"
         ;;
       aix*) # e.g. powerpc-ibm-aix7.1.3.0
@@ -1985,6 +1985,9 @@ AC_DEFUN([GHC_CONVERT_OS],[
       darwin*) # e.g. aarch64-apple-darwin14
         $3="darwin"
         ;;
+      solaris2*)
+        $3="solaris2"
+        ;;
       freebsd*) # like i686-gentoo-freebsd7
                 #      i686-gentoo-freebsd8
                 #      i686-gentoo-freebsd8.2