diff --git a/netwerk/sctp/src/netinet/sctp_asconf.c b/netwerk/sctp/src/netinet/sctp_asconf.c
--- a/netwerk/sctp/src/netinet/sctp_asconf.c
+++ b/netwerk/sctp/src/netinet/sctp_asconf.c
@@ -30,10 +30,18 @@
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  * THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#if defined(_WIN32)
+// Needed for unified build so that rand_s is available to all unified
+// sources.
+#if !defined(_CRT_RAND_S) && !defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION)
+#define _CRT_RAND_S
+#endif
+#endif
+
 #include <netinet/sctp_os.h>
 #include <netinet/sctp_var.h>
 #include <netinet/sctp_sysctl.h>
 #include <netinet/sctp_pcb.h>
 #include <netinet/sctp_header.h>
diff --git a/netwerk/sctp/src/netinet/sctp_bsd_addr.c b/netwerk/sctp/src/netinet/sctp_bsd_addr.c
--- a/netwerk/sctp/src/netinet/sctp_bsd_addr.c
+++ b/netwerk/sctp/src/netinet/sctp_bsd_addr.c
@@ -297,18 +297,11 @@
 }
 
 #endif
 
 #if defined(_WIN32) && defined(__Userspace__)
-#ifdef MALLOC
-#undef MALLOC
-#define MALLOC(x) HeapAlloc(GetProcessHeap(), 0, (x))
-#endif
-#ifdef FREE
-#undef FREE
-#define FREE(x) HeapFree(GetProcessHeap(), 0, (x))
-#endif
+#define SCTP_BSD_FREE(x) HeapFree(GetProcessHeap(), 0, (x))
 static void
 sctp_init_ifns_for_vrf(int vrfid)
 {
 #if defined(INET) || defined(INET6)
 	struct sctp_ifa *sctp_ifa;
@@ -334,11 +327,11 @@
 		return;
 	}
 	/* Get actual adapter information */
 	if ((Err = GetAdaptersAddresses(AF_INET, 0, NULL, pAdapterAddrs, &AdapterAddrsSize)) != ERROR_SUCCESS) {
 		SCTP_PRINTF("GetAdaptersV4Addresses() failed with error code %d\n", Err);
-		FREE(pAdapterAddrs);
+		SCTP_BSD_FREE(pAdapterAddrs);
 		return;
 	}
 	/* Enumerate through each returned adapter and save its information */
 	for (pAdapt = pAdapterAddrs; pAdapt; pAdapt = pAdapt->Next) {
 		if (pAdapt->IfType == IF_TYPE_IEEE80211 || pAdapt->IfType == IF_TYPE_ETHERNET_CSMACD) {
@@ -359,11 +352,11 @@
 					sctp_ifa->localifa_flags &= ~SCTP_ADDR_DEFER_USE;
 				}
 			}
 		}
 	}
-	FREE(pAdapterAddrs);
+	SCTP_BSD_FREE(pAdapterAddrs);
 #endif
 #ifdef INET6
 	AdapterAddrsSize = 0;
 
 	if ((Err = GetAdaptersAddresses(AF_INET6, 0, NULL, NULL, &AdapterAddrsSize)) != 0) {
@@ -379,11 +372,11 @@
 		return;
 	}
 	/* Get actual adapter information */
 	if ((Err = GetAdaptersAddresses(AF_INET6, 0, NULL, pAdapterAddrs, &AdapterAddrsSize)) != ERROR_SUCCESS) {
 		SCTP_PRINTF("GetAdaptersV6Addresses() failed with error code %d\n", Err);
-		FREE(pAdapterAddrs);
+		SCTP_BSD_FREE(pAdapterAddrs);
 		return;
 	}
 	/* Enumerate through each returned adapter and save its information */
 	for (pAdapt = pAdapterAddrs; pAdapt; pAdapt = pAdapt->Next) {
 		if (pAdapt->IfType == IF_TYPE_IEEE80211 || pAdapt->IfType == IF_TYPE_ETHERNET_CSMACD) {
@@ -401,11 +394,11 @@
 					sctp_ifa->localifa_flags &= ~SCTP_ADDR_DEFER_USE;
 				}
 			}
 		}
 	}
-	FREE(pAdapterAddrs);
+	SCTP_BSD_FREE(pAdapterAddrs);
 #endif
 }
 #elif defined(__Userspace__)
 static void
 sctp_init_ifns_for_vrf(int vrfid)
diff --git a/netwerk/sctp/src/user_environment.h b/netwerk/sctp/src/user_environment.h
--- a/netwerk/sctp/src/user_environment.h
+++ b/netwerk/sctp/src/user_environment.h
@@ -28,10 +28,19 @@
  * SUCH DAMAGE.
  */
 
 #ifndef _USER_ENVIRONMENT_H_
 #define _USER_ENVIRONMENT_H_
+
+#if defined(_WIN32)
+// Needed for unified build so that rand_s is available to all unified
+// sources.
+#if !defined(_CRT_RAND_S) && !defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION)
+#define _CRT_RAND_S
+#endif
+#endif
+
 /* __Userspace__ */
 #include <sys/types.h>
 
 #ifdef __FreeBSD__
 #ifndef _SYS_MUTEX_H_