diff --git a/minivhd.h b/minivhd.h
index 590753d..4fba003 100644
--- a/minivhd.h
+++ b/minivhd.h
@@ -4,13 +4,19 @@
 #include <stdio.h>
 #include "minivhd_internal.h"
 
-typedef enum MVHDType
-{
-        MVHD_TYPE_FIXED = 2,
-        MVHD_TYPE_DYNAMIC = 3,
-        MVHD_TYPE_DIFF = 4
+typedef enum MVHDType {
+    MVHD_TYPE_FIXED = 2,
+    MVHD_TYPE_DYNAMIC = 3,
+    MVHD_TYPE_DIFF = 4
 } MVHDType;
 
+typedef enum MVHDError {
+    MVHD_ERR_MEM = -1,
+    MVHD_ERR_FILE,
+    MVHD_ERR_NOT_VHD,
+    MVHD_ERR_TYPE
+} MVHDError;
+
 typedef struct MVHDMeta {
     FILE* f;
     char* filename;
diff --git a/minivhd_manage.c b/minivhd_manage.c
index b343a27..136802d 100644
--- a/minivhd_manage.c
+++ b/minivhd_manage.c
@@ -39,23 +39,23 @@ static void mvhd_read_sparse_header(MVHDMeta* vhdm) {
 MVHDMeta* mvhd_open(const char* path, int* err) {
     MVHDMeta *vhdm = calloc(sizeof *vhdm, 1);
     if (vhdm == NULL) {
-        *err = -1;
+        *err = MVHD_ERR_MEM;
         goto end;
     }
     vhdm->f = fopen64(path, "r+");
     if (vhdm->f == NULL) {
-        *err = -2;
+        *err = MVHD_ERR_FILE;
         goto cleanup_vhdm;
     }
     if (!mvhd_file_is_vhd(vhdm->f)) {
-        *err = -3;
+        *err = MVHD_ERR_NOT_VHD;
         goto cleanup_file;
     }
     mvhd_read_footer(vhdm);
     if (vhdm->footer.disk_type == MVHD_TYPE_DIFF || vhdm->footer.disk_type == MVHD_TYPE_DYNAMIC) {
         mvhd_read_sparse_header(vhdm);
     } else if (vhdm->footer.disk_type != MVHD_TYPE_FIXED) {
-        *err = -4;
+        *err = MVHD_ERR_TYPE;
         goto cleanup_file;
     }
     /* If we've reached this point, we are good to go, so skip the cleanup steps */