diff --git a/Makefile.shared b/Makefile.shared
index 118e8b0..6901fb8 100644
--- a/Makefile.shared
+++ b/Makefile.shared
@@ -31,6 +31,9 @@ ifndef PLATFORM
 	ifneq (,$(findstring -freebsd,$(TARGETMACHINE)))
 		PLATFORM=BSD
 	endif
+	ifneq (,$(findstring -netbsd,$(TARGETMACHINE)))
+		PLATFORM=BSD
+	endif
 	ifneq (,$(findstring -mingw32,$(TARGETMACHINE)))
 		PLATFORM=WINDOWS
 	endif
@@ -96,7 +99,10 @@ ifeq ($(RENDERTYPE),SDL)
 		ifneq (,$(shell $(PKGCONFIG) --atleast-version=3.4 gtk+-3.0 && echo yes))
 			HAVE_GTK=1
 			GTKCONFIG_CFLAGS=-DHAVE_GTK $(shell $(PKGCONFIG) --cflags gtk+-3.0)
-			GTKCONFIG_LIBS=$(shell $(PKGCONFIG) --libs gtk+-3.0) -ldl
+			GTKCONFIG_LIBS=$(shell $(PKGCONFIG) --libs gtk+-3.0)
+			ifeq ($(PLATFORM),LINUX)
+				BUILDLDFLAGS+= -ldl
+			endif
 		else
 			HAVE_GTK=0
 		endif
diff --git a/include/compat.h b/include/compat.h
index 387f121..807e562 100644
--- a/include/compat.h
+++ b/include/compat.h
@@ -37,6 +37,9 @@
 #ifndef _DARWIN_C_SOURCE
 # define _DARWIN_C_SOURCE 1
 #endif
+#ifdef __NetBSD__
+# define _NETBSD_SOURCE 1 // https://gnats.netbsd.org/60227
+#endif
 
 #if defined(_MSC_VER)
 #define _CRT_DECLARE_NONSTDC_NAMES 0
@@ -120,9 +123,9 @@ typedef unsigned __int64 uint64_t;
 #  define B_LITTLE_ENDIAN 0
 #  define B_BIG_ENDIAN    1
 # endif
-# define B_SWAP64(x) __bswap64(x)
-# define B_SWAP32(x) __bswap32(x)
-# define B_SWAP16(x) __bswap16(x)
+# define B_SWAP64(x) bswap64(x)
+# define B_SWAP32(x) bswap32(x)
+# define B_SWAP16(x) bswap16(x)
 
 #elif defined(__APPLE__)
 # if defined(__LITTLE_ENDIAN__)
diff --git a/src/compat.c b/src/compat.c
index a196218..621678f 100644
--- a/src/compat.c
+++ b/src/compat.c
@@ -44,7 +44,7 @@ char *strlwr(char *s)
 {
     char *t = s;
     if (!s) return s;
-    while (*t) { *t = tolower(*t); t++; }
+    while (*t) { *t = tolower((unsigned char)*t); t++; }
     return s;
 }
 
diff --git a/src/mmulti.c b/src/mmulti.c
index 9e0e1bb..93d1fa9 100644
--- a/src/mmulti.c
+++ b/src/mmulti.c
@@ -911,9 +911,11 @@ static int lookuphost(const char *name, struct sockaddr *host, int warnifmany)
 	memset(&hints, 0, sizeof(hints));
 	hints.ai_flags = AI_ADDRCONFIG;
 	hints.ai_family = domain;
+#ifdef AI_V4MAPPED
 	if (domain == PF_INET6) {
 		hints.ai_flags |= AI_V4MAPPED;
 	}
+#endif
 	hints.ai_socktype = SOCK_DGRAM;
 	hints.ai_protocol = IPPROTO_UDP;