diff --git a/config/action.d/hostsdeny.conf b/config/action.d/hostsdeny.conf
index b04f2adb..db36aa29 100644
--- a/config/action.d/hostsdeny.conf
+++ b/config/action.d/hostsdeny.conf
@@ -40,7 +40,11 @@ actionban = IP=<ip> &&
 # Tags:    See jail.conf(5) man page
 # Values:  CMD
 #
-actionunban = IP=<ip> && sed -i.old /ALL:\ $IP/d <file>
+# Original:
+#actionunban = IP=<ip> && sed -i.old /ALL:\ $IP/d <file>
+
+# -i is not supported under Solaris 10/OpenSolaris
+actionunban = IP=<ip> && perl -ne "print unless (/^ALL:\s$IP/)" -i <file>
 
 [Init]