diff --git a/src/debug.h b/src/debug.h
index 1532be824..ba2e8704e 100644
--- a/src/debug.h
+++ b/src/debug.h
@@ -72,6 +72,14 @@ extern std::ostream dstream;
 extern std::ostream dstream_no_stderr;
 extern Nullstream dummyout;
 
+/*
+	Include assert.h and immediately undef assert so that it can't override
+	our assert later on. leveldb/slice.h is a notable offender.
+*/
+
+#include <assert.h>
+#undef assert
+
 /*
 	Assert
 */