diff --git a/main.cpp b/main.cpp
index b50422b..b3af634 100644
--- a/main.cpp
+++ b/main.cpp
@@ -478,41 +478,31 @@ void do_read_parallel(char *map, long long len, long long initial_offset, const
 }
 
 static ssize_t read_stream(json_pull *j, char *buffer, size_t n);
-#define BUF 262144
 
 struct STREAM {
-	FILE *fp;
-
-	bool gz;
-	z_stream inflate_s;
-	Bytef buf[BUF];
-	std::vector<unsigned char> ahead;
+	FILE *fp = NULL;
+	gzFile gz = NULL;
 
 	int fclose() {
-		if (gz) {
-			inflateEnd(&inflate_s);
+		int ret;
+
+		if (gz != NULL) {
+			ret = gzclose(gz);
+		} else {
+			ret = ::fclose(fp);
 		}
 
-		int ret = ::fclose(fp);
 		delete this;
 		return ret;
 	}
 
 	int peekc() {
-		if (gz) {
-			if (ahead.size() > 0) {
-				return ahead[ahead.size() - 1];
+		if (gz != NULL) {
+			int c = gzgetc(gz);
+			if (c != EOF) {
+				gzungetc(c, gz);
 			}
-
-			char tmp[1];
-			size_t nread = read(tmp, 1);
-
-			if (nread == 0) {
-				return EOF;
-			}
-
-			ahead.push_back(tmp[0]);
-			return (unsigned char) tmp[0];
+			return c;
 		} else {
 			int c = getc(fp);
 			if (c != EOF) {
@@ -523,53 +513,13 @@ struct STREAM {
 	}
 
 	size_t read(char *out, size_t count) {
-		if (gz) {
-			if (ahead.size() > 0 && count > 0) {
-				out[0] = ahead[ahead.size() - 1];
-				ahead.resize(ahead.size() - 1);
-				return 1;
-			}
-
-			while (true) {
-				// Move any existing readahead to the start
-				memmove(buf, inflate_s.next_in, inflate_s.avail_in);
-				inflate_s.next_in = buf;
-
-				// Read more compressed data if there is room and availability
-				bool eof = false;
-				if (inflate_s.avail_in < BUF) {
-					size_t nread = ::fread(inflate_s.next_in + inflate_s.avail_in, sizeof(char), BUF - inflate_s.avail_in, fp);
-					inflate_s.avail_in += nread;
-
-					if (nread == 0) {
-						eof = true;
-					}
-				}
-
-				inflate_s.avail_out = count;
-				inflate_s.next_out = (Bytef *) out;
-
-				int ret = inflate(&inflate_s, Z_SYNC_FLUSH);
-
-				if (ret == Z_STREAM_ERROR || ret == Z_MEM_ERROR || ret == Z_DATA_ERROR) {
-					fprintf(stderr, "%s: Decompression error %s\n", *av, inflate_s.msg);
-					exit(EXIT_FAILURE);
-				}
-
-				if (inflate_s.next_out != (Bytef *) out) {
-					size_t n = inflate_s.next_out - (Bytef *) out;
-					return n;
-				}
-
-				if (ret == Z_STREAM_END) {
-					return 0;
-				}
-
-				if (eof) {
-					fprintf(stderr, "%s: Compressed data was truncated\n", *av);
-					exit(EXIT_FAILURE);
-				}
+		if (gz != NULL) {
+			int ret = gzread(gz, out, count);
+			if (ret < 0) {
+				fprintf(stderr, "%s: Error reading compressed data\n", *av);
+				exit(EXIT_FAILURE);
 			}
+			return ret;
 		} else {
 			return ::fread(out, 1, count, fp);
 		}
@@ -585,30 +535,22 @@ static ssize_t read_stream(json_pull *j, char *buffer, size_t n) {
 }
 
 STREAM *streamfdopen(int fd, const char *mode, std::string const &fname) {
-	FILE *fp = fdopen(fd, mode);
-	if (fp == NULL) {
-		return NULL;
-	}
-
 	STREAM *s = new STREAM;
-	s->fp = fp;
-	s->gz = false;
+	s->fp = NULL;
+	s->gz = NULL;
 
 	if (fname.size() > 3 && fname.substr(fname.size() - 3) == std::string(".gz")) {
-		s->inflate_s.zalloc = Z_NULL;
-		s->inflate_s.zfree = Z_NULL;
-		s->inflate_s.opaque = Z_NULL;
-		s->inflate_s.avail_in = 0;
-		s->inflate_s.next_in = Z_NULL;
-
-		if (inflateInit2(&s->inflate_s, 32 + 15) != Z_OK) {
-			fprintf(stderr, "%s: %s: Decompression error %s\n", *av, fname.c_str(), s->inflate_s.msg);
+		s->gz = gzdopen(fd, mode);
+		if (s->gz == NULL) {
+			fprintf(stderr, "%s: %s: Decompression error\n", *av, fname.c_str());
+			exit(EXIT_FAILURE);
+		}
+	} else {
+		s->fp = fdopen(fd, mode);
+		if (s->fp == NULL) {
+			perror(fname.c_str());
 			exit(EXIT_FAILURE);
 		}
-
-		s->inflate_s.next_in = s->buf;
-		s->inflate_s.avail_in = 0;
-		s->gz = true;
 	}
 
 	return s;
@@ -617,7 +559,7 @@ STREAM *streamfdopen(int fd, const char *mode, std::string const &fname) {
 STREAM *streamfpopen(FILE *fp) {
 	STREAM *s = new STREAM;
 	s->fp = fp;
-	s->gz = false;
+	s->gz = NULL;
 
 	return s;
 }