diff --git a/include/sys/types.h b/include/sys/types.h
index 89310f0..2dfac13 100644
--- a/include/sys/types.h
+++ b/include/sys/types.h
@@ -8,7 +8,6 @@
 #ifndef LIBCRYPTOCOMPAT_SYS_TYPES_H
 #define LIBCRYPTOCOMPAT_SYS_TYPES_H
 
-#include <db.h>
 #include <stdint.h>
 
 #ifdef __MINGW32__
@@ -23,4 +22,12 @@
 # define __bounded__(x, y, z)
 #endif
 
+/*
+ * Define BSD-style unsigned bits types for systems that do not have them.
+ */
+typedef uint8_t     u_int8_t;
+typedef uint16_t    u_int16_t;
+typedef uint32_t    u_int32_t;
+typedef uint64_t    u_int64_t;
+
 #endif