diff --git a/src/rvprof_internal.h b/src/rvprof_internal.h
index 3769bfc..af6dde0 100644
--- a/src/rvprof_internal.h
+++ b/src/rvprof_internal.h
@@ -21,7 +21,16 @@ extern "C"{
 #define MAX_NAME_LEN 64
 
 
-
+// error enum
+typedef enum {
+    RVPROF_SUCCESS = 0,
+    RVPROF_ERROR_MEMORY = -1,
+    RVPROF_ERROR_IO = -2,
+    RVPROF_ERROR_SYMBOLS = -3,
+    RVPROF_ERROR_INVALID_STATE = -4,
+    RVPROF_ERROR_STACK_OVERFLOW = -5,
+    RVPROF_ERROR_STACK_UNDERFLOW = -6
+} rvprof_error_t
 
 
 #ifdef __cplusplus