diff --git a/debug/full_flush.c b/debug/full_flush.c
index ce0d2e8..67442b1 100644
--- a/debug/full_flush.c
+++ b/debug/full_flush.c
@@ -29,7 +29,7 @@ encode(size_t size, lzma_action action)
 
 	do {
 		if (strm.avail_in == 0 && size > 0) {
-			const size_t amount = MIN(size, CHUNK);
+			const size_t amount = my_min(size, CHUNK);
 			strm.avail_in = fread(in, 1, amount, file_in);
 			strm.next_in = in;
 			size -= amount; // Intentionally not using avail_in.
diff --git a/debug/sync_flush.c b/debug/sync_flush.c
index a094ef7..fc2ebcb 100644
--- a/debug/sync_flush.c
+++ b/debug/sync_flush.c
@@ -29,7 +29,7 @@ encode(size_t size, lzma_action action)
 
 	do {
 		if (strm.avail_in == 0 && size > 0) {
-			const size_t amount = MIN(size, CHUNK);
+			const size_t amount = my_min(size, CHUNK);
 			strm.avail_in = fread(in, 1, amount, file_in);
 			strm.next_in = in;
 			size -= amount; // Intentionally not using avail_in.
diff --git a/src/common/sysdefs.h b/src/common/sysdefs.h
index 61ac0b4..1e138b1 100644
--- a/src/common/sysdefs.h
+++ b/src/common/sysdefs.h
@@ -156,13 +156,11 @@ typedef unsigned char _Bool;
 #undef memzero
 #define memzero(s, n) memset(s, 0, n)
 
-#ifndef MIN
-#	define MIN(x, y) ((x) < (y) ? (x) : (y))
-#endif
-
-#ifndef MAX
-#	define MAX(x, y) ((x) > (y) ? (x) : (y))
-#endif
+// NOTE: Avoid using MIN() and MAX(), because even conditionally defining
+// those macros can cause some portability trouble, since on some systems
+// the system headers insist defining their own versions.
+#define my_min(x, y) ((x) < (y) ? (x) : (y))
+#define my_max(x, y) ((x) > (y) ? (x) : (y))
 
 #ifndef ARRAY_SIZE
 #	define ARRAY_SIZE(array) (sizeof(array) / sizeof((array)[0]))
diff --git a/src/liblzma/common/block_buffer_encoder.c b/src/liblzma/common/block_buffer_encoder.c
index 4d90fee..a8f71c2 100644
--- a/src/liblzma/common/block_buffer_encoder.c
+++ b/src/liblzma/common/block_buffer_encoder.c
@@ -139,7 +139,7 @@ block_encode_uncompressed(lzma_block *block, const uint8_t *in, size_t in_size,
 
 		// Size of the uncompressed chunk
 		const size_t copy_size
-				= MIN(in_size - in_pos, LZMA2_CHUNK_MAX);
+				= my_min(in_size - in_pos, LZMA2_CHUNK_MAX);
 		out[(*out_pos)++] = (copy_size - 1) >> 8;
 		out[(*out_pos)++] = (copy_size - 1) & 0xFF;
 
diff --git a/src/liblzma/common/common.c b/src/liblzma/common/common.c
index 2f185e4..07b1d47 100644
--- a/src/liblzma/common/common.c
+++ b/src/liblzma/common/common.c
@@ -76,7 +76,7 @@ lzma_bufcpy(const uint8_t *restrict in, size_t *restrict in_pos,
 {
 	const size_t in_avail = in_size - *in_pos;
 	const size_t out_avail = out_size - *out_pos;
-	const size_t copy_size = MIN(in_avail, out_avail);
+	const size_t copy_size = my_min(in_avail, out_avail);
 
 	memcpy(out + *out_pos, in + *in_pos, copy_size);
 
diff --git a/src/liblzma/common/stream_buffer_encoder.c b/src/liblzma/common/stream_buffer_encoder.c
index bbafaa6..f727d85 100644
--- a/src/liblzma/common/stream_buffer_encoder.c
+++ b/src/liblzma/common/stream_buffer_encoder.c
@@ -33,7 +33,7 @@ lzma_stream_buffer_bound(size_t uncompressed_size)
 	// Catch the possible integer overflow and also prevent the size of
 	// the Stream exceeding LZMA_VLI_MAX (theoretically possible on
 	// 64-bit systems).
-	if (MIN(SIZE_MAX, LZMA_VLI_MAX) - block_bound < HEADERS_BOUND)
+	if (my_min(SIZE_MAX, LZMA_VLI_MAX) - block_bound < HEADERS_BOUND)
 		return 0;
 
 	return block_bound + HEADERS_BOUND;
diff --git a/src/liblzma/delta/delta_encoder.c b/src/liblzma/delta/delta_encoder.c
index 80d0d17..ea1cc2c 100644
--- a/src/liblzma/delta/delta_encoder.c
+++ b/src/liblzma/delta/delta_encoder.c
@@ -59,7 +59,7 @@ delta_encode(lzma_coder *coder, lzma_allocator *allocator,
 	if (coder->next.code == NULL) {
 		const size_t in_avail = in_size - *in_pos;
 		const size_t out_avail = out_size - *out_pos;
-		const size_t size = MIN(in_avail, out_avail);
+		const size_t size = my_min(in_avail, out_avail);
 
 		copy_and_encode(coder, in + *in_pos, out + *out_pos, size);
 
diff --git a/src/liblzma/lz/lz_decoder.c b/src/liblzma/lz/lz_decoder.c
index 350b1f8..2c57355 100644
--- a/src/liblzma/lz/lz_decoder.c
+++ b/src/liblzma/lz/lz_decoder.c
@@ -81,8 +81,9 @@ decode_buffer(lzma_coder *coder,
 		// It must not decode past the end of the dictionary
 		// buffer, and we don't want it to decode more than is
 		// actually needed to fill the out[] buffer.
-		coder->dict.limit = coder->dict.pos + MIN(out_size - *out_pos,
-				coder->dict.size - coder->dict.pos);
+		coder->dict.limit = coder->dict.pos
+				+ my_min(out_size - *out_pos,
+					coder->dict.size - coder->dict.pos);
 
 		// Call the coder->lz.code() to do the actual decoding.
 		const lzma_ret ret = coder->lz.code(
@@ -264,7 +265,7 @@ lzma_lz_decoder_init(lzma_next_coder *next, lzma_allocator *allocator,
 			&& lz_options.preset_dict_size > 0) {
 		// If the preset dictionary is bigger than the actual
 		// dictionary, copy only the tail.
-		const size_t copy_size = MIN(lz_options.preset_dict_size,
+		const size_t copy_size = my_min(lz_options.preset_dict_size,
 				lz_options.dict_size);
 		const size_t offset = lz_options.preset_dict_size - copy_size;
 		memcpy(next->coder->dict.buf, lz_options.preset_dict + offset,
diff --git a/src/liblzma/lz/lz_decoder.h b/src/liblzma/lz/lz_decoder.h
index bf1609d..7266e80 100644
--- a/src/liblzma/lz/lz_decoder.h
+++ b/src/liblzma/lz/lz_decoder.h
@@ -129,7 +129,7 @@ dict_repeat(lzma_dict *dict, uint32_t distance, uint32_t *len)
 {
 	// Don't write past the end of the dictionary.
 	const size_t dict_avail = dict->limit - dict->pos;
-	uint32_t left = MIN(dict_avail, *len);
+	uint32_t left = my_min(dict_avail, *len);
 	*len -= left;
 
 	// Repeat a block of data from the history. Because memcpy() is faster
diff --git a/src/liblzma/lz/lz_encoder.c b/src/liblzma/lz/lz_encoder.c
index 757e537..691fe72 100644
--- a/src/liblzma/lz/lz_encoder.c
+++ b/src/liblzma/lz/lz_encoder.c
@@ -423,7 +423,7 @@ lz_encoder_init(lzma_mf *mf, lzma_allocator *allocator,
 			&& lz_options->preset_dict_size > 0) {
 		// If the preset dictionary is bigger than the actual
 		// dictionary, use only the tail.
-		mf->write_pos = MIN(lz_options->preset_dict_size, mf->size);
+		mf->write_pos = my_min(lz_options->preset_dict_size, mf->size);
 		memcpy(mf->buffer, lz_options->preset_dict
 				+ lz_options->preset_dict_size - mf->write_pos,
 				mf->write_pos);
diff --git a/src/liblzma/lz/lz_encoder.h b/src/liblzma/lz/lz_encoder.h
index f6352a4..741c453 100644
--- a/src/liblzma/lz/lz_encoder.h
+++ b/src/liblzma/lz/lz_encoder.h
@@ -281,7 +281,7 @@ mf_read(lzma_mf *mf, uint8_t *out, size_t *out_pos, size_t out_size,
 		size_t *left)
 {
 	const size_t out_avail = out_size - *out_pos;
-	const size_t copy_size = MIN(out_avail, *left);
+	const size_t copy_size = my_min(out_avail, *left);
 
 	assert(mf->read_ahead == 0);
 	assert(mf->read_pos >= *left);
diff --git a/src/liblzma/lz/lz_encoder_mf.c b/src/liblzma/lz/lz_encoder_mf.c
index b31b085..f82a1c1 100644
--- a/src/liblzma/lz/lz_encoder_mf.c
+++ b/src/liblzma/lz/lz_encoder_mf.c
@@ -481,7 +481,7 @@ bt_find_func(
 				<< 1);
 
 		const uint8_t *const pb = cur - delta;
-		uint32_t len = MIN(len0, len1);
+		uint32_t len = my_min(len0, len1);
 
 		if (pb[len] == cur[len]) {
 			while (++len != len_limit)
@@ -546,7 +546,7 @@ bt_skip_func(
 				+ (delta > cyclic_pos ? cyclic_size : 0))
 				<< 1);
 		const uint8_t *pb = cur - delta;
-		uint32_t len = MIN(len0, len1);
+		uint32_t len = my_min(len0, len1);
 
 		if (pb[len] == cur[len]) {
 			while (++len != len_limit)
diff --git a/src/liblzma/lzma/lzma2_encoder.c b/src/liblzma/lzma/lzma2_encoder.c
index 1e0569a..b48e0d6 100644
--- a/src/liblzma/lzma/lzma2_encoder.c
+++ b/src/liblzma/lzma/lzma2_encoder.c
@@ -372,7 +372,7 @@ extern lzma_ret
 lzma_lzma2_props_encode(const void *options, uint8_t *out)
 {
 	const lzma_options_lzma *const opt = options;
-	uint32_t d = MAX(opt->dict_size, LZMA_DICT_SIZE_MIN);
+	uint32_t d = my_max(opt->dict_size, LZMA_DICT_SIZE_MIN);
 
 	// Round up to to the next 2^n - 1 or 2^n + 2^(n - 1) - 1 depending
 	// on which one is the next:
diff --git a/src/liblzma/lzma/lzma_encoder_optimum_fast.c b/src/liblzma/lzma/lzma_encoder_optimum_fast.c
index 4ca55b6..f835f69 100644
--- a/src/liblzma/lzma/lzma_encoder_optimum_fast.c
+++ b/src/liblzma/lzma/lzma_encoder_optimum_fast.c
@@ -33,7 +33,7 @@ lzma_lzma_optimum_fast(lzma_coder *restrict coder, lzma_mf *restrict mf,
 	}
 
 	const uint8_t *buf = mf_ptr(mf) - 1;
-	const uint32_t buf_avail = MIN(mf_avail(mf) + 1, MATCH_LEN_MAX);
+	const uint32_t buf_avail = my_min(mf_avail(mf) + 1, MATCH_LEN_MAX);
 
 	if (buf_avail < 2) {
 		// There's not enough input left to encode a match.
diff --git a/src/liblzma/lzma/lzma_encoder_optimum_normal.c b/src/liblzma/lzma/lzma_encoder_optimum_normal.c
index 9284c8a..7e85649 100644
--- a/src/liblzma/lzma/lzma_encoder_optimum_normal.c
+++ b/src/liblzma/lzma/lzma_encoder_optimum_normal.c
@@ -287,7 +287,7 @@ helper1(lzma_coder *restrict coder, lzma_mf *restrict mf,
 		matches_count = coder->matches_count;
 	}
 
-	const uint32_t buf_avail = MIN(mf_avail(mf) + 1, MATCH_LEN_MAX);
+	const uint32_t buf_avail = my_min(mf_avail(mf) + 1, MATCH_LEN_MAX);
 	if (buf_avail < 2) {
 		*back_res = UINT32_MAX;
 		*len_res = 1;
@@ -371,7 +371,7 @@ helper1(lzma_coder *restrict coder, lzma_mf *restrict mf,
 		}
 	}
 
-	const uint32_t len_end = MAX(len_main, rep_lens[rep_max_index]);
+	const uint32_t len_end = my_max(len_main, rep_lens[rep_max_index]);
 
 	if (len_end < 2) {
 		*back_res = coder->opts[1].back_prev;
@@ -565,12 +565,12 @@ helper2(lzma_coder *coder, uint32_t *reps, const uint8_t *buf,
 	if (buf_avail_full < 2)
 		return len_end;
 
-	const uint32_t buf_avail = MIN(buf_avail_full, nice_len);
+	const uint32_t buf_avail = my_min(buf_avail_full, nice_len);
 
 	if (!next_is_literal && match_byte != current_byte) { // speed optimization
 		// try literal + rep0
 		const uint8_t *const buf_back = buf - reps[0] - 1;
-		const uint32_t limit = MIN(buf_avail_full, nice_len + 1);
+		const uint32_t limit = my_min(buf_avail_full, nice_len + 1);
 
 		uint32_t len_test = 1;
 		while (len_test < limit && buf[len_test] == buf_back[len_test])
@@ -648,7 +648,7 @@ helper2(lzma_coder *coder, uint32_t *reps, const uint8_t *buf,
 
 
 		uint32_t len_test_2 = len_test + 1;
-		const uint32_t limit = MIN(buf_avail_full,
+		const uint32_t limit = my_min(buf_avail_full,
 				len_test_2 + nice_len);
 		for (; len_test_2 < limit
 				&& buf[len_test_2] == buf_back[len_test_2];
@@ -743,7 +743,7 @@ helper2(lzma_coder *coder, uint32_t *reps, const uint8_t *buf,
 				// Try Match + Literal + Rep0
 				const uint8_t *const buf_back = buf - cur_back - 1;
 				uint32_t len_test_2 = len_test + 1;
-				const uint32_t limit = MIN(buf_avail_full,
+				const uint32_t limit = my_min(buf_avail_full,
 						len_test_2 + nice_len);
 
 				for (; len_test_2 < limit &&
@@ -860,7 +860,7 @@ lzma_lzma_optimum_normal(lzma_coder *restrict coder, lzma_mf *restrict mf,
 
 		len_end = helper2(coder, reps, mf_ptr(mf) - 1, len_end,
 				position + cur, cur, mf->nice_len,
-				MIN(mf_avail(mf) + 1, OPTS - 1 - cur));
+				my_min(mf_avail(mf) + 1, OPTS - 1 - cur));
 	}
 
 	backward(coder, len_res, back_res, cur);
diff --git a/src/xz/args.c b/src/xz/args.c
index fdd63b4..7b12529 100644
--- a/src/xz/args.c
+++ b/src/xz/args.c
@@ -406,7 +406,8 @@ parse_environment(args_info *args, char *argv0)
 
 			// Keep argc small enough to fit into a singed int
 			// and to keep it usable for memory allocation.
-			if (++argc == MIN(INT_MAX, SIZE_MAX / sizeof(char *)))
+			if (++argc == my_min(
+					INT_MAX, SIZE_MAX / sizeof(char *)))
 				message_fatal(_("The environment variable "
 						"XZ_OPT contains too many "
 						"arguments"));