diff --git a/include/util.h b/include/util.h
index 7a2b3083..b7bace58 100644
--- a/include/util.h
+++ b/include/util.h
@@ -124,17 +124,6 @@ bool path_exists(const char *path);
  */
 void i3_restart(bool forget_layout);
 
-#if defined(__OpenBSD__) || defined(__APPLE__)
-
-/**
- * Taken from FreeBSD
- * Find the first occurrence of the byte string s in byte string l.
- *
- */
-void *memmem(const void *l, size_t l_len, const void *s, size_t s_len);
-
-#endif
-
 /**
  * Escapes the given string if a pango font is currently used.
  * If the string has to be escaped, the input string will be free'd.
diff --git a/src/util.c b/src/util.c
index 812aad37..c3dae6a5 100644
--- a/src/util.c
+++ b/src/util.c
@@ -312,42 +312,6 @@ void i3_restart(bool forget_layout) {
     /* not reached */
 }
 
-#if defined(__OpenBSD__) || defined(__APPLE__)
-
-/*
- * Taken from FreeBSD
- * Find the first occurrence of the byte string s in byte string l.
- *
- */
-void *memmem(const void *l, size_t l_len, const void *s, size_t s_len) {
-    register char *cur, *last;
-    const char *cl = (const char *)l;
-    const char *cs = (const char *)s;
-
-    /* we need something to compare */
-    if (l_len == 0 || s_len == 0)
-        return NULL;
-
-    /* "s" must be smaller or equal to "l" */
-    if (l_len < s_len)
-        return NULL;
-
-    /* special case where s_len == 1 */
-    if (s_len == 1)
-        return memchr(l, (int)*cs, l_len);
-
-    /* the last position where its possible to find "s" in "l" */
-    last = (char *)cl + l_len - s_len;
-
-    for (cur = (char *)cl; cur <= last; cur++)
-        if (cur[0] == cs[0] && memcmp(cur, cs, s_len) == 0)
-            return cur;
-
-    return NULL;
-}
-
-#endif
-
 /*
  * Escapes the given string if a pango font is currently used.
  * If the string has to be escaped, the input string will be free'd.