diff --git a/libhtp/configure.ac b/libhtp/configure.ac
index 192bd31902..4ac482bb9b 100644
--- a/libhtp/configure.ac
+++ b/libhtp/configure.ac
@@ -94,6 +94,22 @@ AC_MSG_RESULT(yes),
 AC_MSG_RESULT(no))
 LDFLAGS="${TMPLDFLAGS}"
 
+
+#check for os
+AC_MSG_CHECKING([host os])
+
+# If no host os was detected, try with uname
+if test -z "$host" ; then
+        host="`uname`"
+fi
+case "$host" in
+       *-*-openbsd*)
+                CFLAGS="${CFLAGS} -fgnu89-inline"
+       ;;
+esac
+AC_MSG_RESULT(ok)
+
+
 dnl -----------------------------------------------
 dnl forces all relocations to be resolved at run-time
 dnl -----------------------------------------------