diff --git a/configure.in b/configure.in
index 17bc82b..4008d2c 100644
--- a/configure.in
+++ b/configure.in
@@ -832,7 +832,7 @@
 # tweak OPT based on compiler and platform, only if the user didn't set
 # it on the command line
 AC_SUBST(OPT)
-if test "${OPT-unset}" == "unset"
+if test "${OPT-unset}" = "unset"
 then
     case $GCC in
     yes)