diff --git a/src/assembler/assemble.c b/src/assembler/assemble.c
index 4774d15..cefc25d 100644
--- a/src/assembler/assemble.c
+++ b/src/assembler/assemble.c
@@ -211,6 +211,32 @@ void serializeProgramToFile(Program* program, const char* outputFileName) {
         exit(1);
     }
 
+    // Write magic header
+    size_t written = fwrite("mlc\0", 4, 1, fp);
+    if (written != 1) {
+        fprintf(stderr, "failed to write magic header into file %s\n", outputFileName);
+        fclose(fp);
+        exit(1);
+    }
+
+    // Write program version
+    uint8_t version = 1;
+    written = fwrite(&version, sizeof(uint8_t), 1, fp);
+    if (written != 1) {
+        fprintf(stderr, "failed to write version header into file %s\n", outputFileName);
+        fclose(fp);
+        exit(1);
+    }
+
+    // Write instruction count
+    uint32_t instCount = program->len;
+    written = fwrite(&instCount, sizeof(uint32_t), 1, fp);
+    if (written != 1) {
+        fprintf(stderr, "failed to write instruction count header into file %s\n", outputFileName);
+        fclose(fp);
+        exit(1);
+    }
+
     for (size_t i = 0; i < program->len; i++) {
         Instruction* inst = &program->at[i];