diff --git a/src/network/network.cpp b/src/network/network.cpp
index 0b7657ff9a..925fc667ce 100644
--- a/src/network/network.cpp
+++ b/src/network/network.cpp
@@ -1278,13 +1278,22 @@ void Network::Server_Send_MAP(NetworkConnection* connection)
 	size_t chunksize = 1000;
 	size_t out_size;
 	unsigned char *compressed = util_zlib_deflate(&buffer[0], size, &out_size);
-	unsigned char *header = (unsigned char *)_strdup("open2_sv6_zlib");
-	size_t header_len = strlen((char *)header) + 1; // account for null terminator
-	header = (unsigned char *)realloc(header, header_len + out_size);
-	memcpy(&header[header_len], compressed, out_size);
-	out_size += header_len;
-	free(compressed);
-	log_verbose("Sending map of size %u bytes, compressed to %u bytes", size, out_size);
+	unsigned char *header;
+	if (compressed != NULL)
+	{
+		header = (unsigned char *)_strdup("open2_sv6_zlib");
+		size_t header_len = strlen((char *)header) + 1; // account for null terminator
+		header = (unsigned char *)realloc(header, header_len + out_size);
+		memcpy(&header[header_len], compressed, out_size);
+		out_size += header_len;
+		free(compressed);
+		log_verbose("Sending map of size %u bytes, compressed to %u bytes", size, out_size);
+	} else {
+		log_warning("Failed to compress the data, falling back to non-compressed sv6.");
+		header = (unsigned char *)malloc(size);
+		out_size = size;
+		memcpy(header, &buffer[0], size);
+	}
 	for (size_t i = 0; i < out_size; i += chunksize) {
 		int datasize = (std::min)(chunksize, out_size - i);
 		std::unique_ptr<NetworkPacket> packet = std::move(NetworkPacket::Allocate());
diff --git a/src/util/util.c b/src/util/util.c
index d2f2b35d5a..d41ab40cd4 100644
--- a/src/util/util.c
+++ b/src/util/util.c
@@ -347,6 +347,10 @@ unsigned char *util_zlib_inflate(unsigned char *data, size_t data_in_size, size_
 			buffer_size *= 2;
 			out_size = buffer_size;
 			buffer = realloc(buffer, buffer_size);
+		} else if (ret == Z_STREAM_ERROR) {
+			log_error("Your build is shipped with broken zlib. Please use the official build.");
+			free(buffer);
+			return NULL;
 		}
 		ret = uncompress(buffer, &out_size, data, data_in_size);
 	} while (ret != Z_OK);
@@ -377,12 +381,8 @@ unsigned char *util_zlib_deflate(unsigned char *data, size_t data_in_size, size_
 			buffer = realloc(buffer, buffer_size);
 		} else if (ret == Z_STREAM_ERROR) {
 			log_error("Your build is shipped with broken zlib. Please use the official build.");
-			log_error("Falling back to non-compressed sv6.");
-			buffer = realloc(buffer, data_in_size);
-			memcpy(buffer, data, data_in_size);
-			out_size = data_in_size;
-			ret = Z_OK;
-			break;
+			free(buffer);
+			return NULL;
 		}
 		ret = compress(buffer, &out_size, data, data_in_size);
 	} while (ret != Z_OK);