diff --git a/lib/gssapi/test_context.c b/lib/gssapi/test_context.c
index 82ac5f948..70c68185a 100644
--- a/lib/gssapi/test_context.c
+++ b/lib/gssapi/test_context.c
@@ -71,12 +71,21 @@ static struct {
     const char *name;
     gss_OID oid;
 } o2n[] = {
-    { "krb5", GSS_KRB5_MECHANISM },
-    { "spnego", GSS_SPNEGO_MECHANISM },
-    { "ntlm", GSS_NTLM_MECHANISM },
-    { "sasl-digest-md5", GSS_SASL_DIGEST_MD5_MECHANISM }
+    { "krb5", NULL /* GSS_KRB5_MECHANISM */ },
+    { "spnego", NULL /* GSS_SPNEGO_MECHANISM */ },
+    { "ntlm", NULL /* GSS_NTLM_MECHANISM */ },
+    { "sasl-digest-md5", NULL /* GSS_SASL_DIGEST_MD5_MECHANISM */ }
 };
 
+static void
+init_o2n(void)
+{
+    o2n[0].oid = GSS_KRB5_MECHANISM;
+    o2n[1].oid = GSS_SPNEGO_MECHANISM;
+    o2n[2].oid = GSS_NTLM_MECHANISM;
+    o2n[3].oid = GSS_SASL_DIGEST_MD5_MECHANISM;
+}
+
 static gss_OID
 string_to_oid(const char *name)
 {
@@ -499,6 +508,8 @@ main(int argc, char **argv)
 
     setprogname(argv[0]);
 
+    init_o2n();
+
     if (krb5_init_context(&context))
 	errx(1, "krb5_init_context");