diff --git a/jv.c b/jv.c
index d1ae8d90..2530d7fc 100644
--- a/jv.c
+++ b/jv.c
@@ -586,6 +586,10 @@ int jv_string_length_codepoints(jv j) {
 }
 
 #ifndef HAVE_MEMMEM
+#ifdef memmem
+#undef memmem
+#endif
+#define memmem my_memmem
 static const void *memmem(const void *haystack, size_t haystacklen,
                           const void *needle, size_t needlelen)
 {