diff --git a/CMakeLists.txt b/CMakeLists.txt
index f744169..13b51a7 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -4,10 +4,9 @@ project(simple-protobuf)
 include(TestBigEndian)
 test_big_endian(isBigEndian)
 if (${isBigEndian})
-    add_library(spb SHARED protobuf_be.c)
-else()
-    add_library(spb SHARED protobuf_le.c)
+    add_definitions(-DWORDS_BIGENDIAN)
 endif()
 
+add_library(spb SHARED protobuf.c)
 add_executable(test test.c)
 target_link_libraries(test spb)
\ No newline at end of file
diff --git a/protobuf_le.c b/protobuf.c
similarity index 89%
rename from protobuf_le.c
rename to protobuf.c
index c8e0b83..e7a5ec8 100644
--- a/protobuf_le.c
+++ b/protobuf.c
@@ -19,9 +19,14 @@ static uint64_t read_num(FILE* fp) {
 static int write_num(FILE* fp, uint64_t n) {
     char* c = (char*)(&n);
     int i = 0;
-    while(*c) {
-        int ch = *c & 0x7f;
-        if(c[1]) ch |= 0x80;
+    while(n > 0) {
+        #ifdef WORDS_BIGENDIAN
+            int ch = c[7] & 0x7f;
+            if(c[6]) ch |= 0x80;
+        #else
+            int ch = *c & 0x7f;
+            if(c[1]) ch |= 0x80;
+        #endif
         fputc(ch, fp);
         n >>= 7;
         i++;