diff --git a/include/unicorn/unicorn.h b/include/unicorn/unicorn.h
index 8b76781a..f3c6e344 100644
--- a/include/unicorn/unicorn.h
+++ b/include/unicorn/unicorn.h
@@ -143,7 +143,7 @@ typedef enum uc_err {
 
 // Runtime option for the Unicorn engine
 typedef enum uc_opt_type {
-	UC_OPT_WINDOWS_TIB = 1,	// Setup Windows Thread Information Block
+    UC_OPT_WINDOWS_TIB = 1,	// Setup Windows Thread Information Block
 } uc_opt_type;
 
 
diff --git a/uc.c b/uc.c
index c1b2f454..d038ce99 100644
--- a/uc.c
+++ b/uc.c
@@ -96,6 +96,8 @@ const char *uc_strerror(uc_err code)
             return "Fetch from unaligned memory (UC_ERR_FETCH_UNALIGNED)";
         case UC_ERR_RESOURCE:
             return "Insufficient resource (UC_ERR_RESOURCE)";
+        case UC_ERR_OPT_INVALID:
+            return "Invalid option (UC_ERR_OPT_INVALID)";
     }
 }