diff --git a/configure.in b/configure.in
index d3f2654a83..acedafc7af 100644
--- a/configure.in
+++ b/configure.in
@@ -502,6 +502,8 @@ AC_CHECK_SIZEOF(__int64)
 AC_CHECK_SIZEOF(void *)
 AC_CHECK_SIZEOF(time_t)
 
+AC_CHECK_TYPES([uint, u_char])
+
 if test -z "$CROSS_COMPILE"; then
 AC_CACHE_CHECK([whether time_t is signed], tor_cv_time_t_signed, [
 AC_TRY_RUN([
diff --git a/src/or/eventdns_tor.h b/src/or/eventdns_tor.h
index e32a190bb4..a10b3726bb 100644
--- a/src/or/eventdns_tor.h
+++ b/src/or/eventdns_tor.h
@@ -1,8 +1,12 @@
 
 #include "orconfig.h"
 #define DNS_USE_OPENSSL_FOR_ID
+#ifndef HAVE_UINT
 typedef unsigned int uint;
+#endif
+#ifndef HAVE_U_CHAR
 typedef unsigned char u_char;
+#endif
 #ifdef MS_WINDOWS
 #define inline __inline
 #endif