diff --git a/src/sf_define.h b/src/sf_define.h
index c823634..19787cb 100644
--- a/src/sf_define.h
+++ b/src/sf_define.h
@@ -65,6 +65,7 @@
 #define SF_ERROR_EBUSY        8816
 #define SF_ERROR_EINVAL       8822
 #define SF_ERROR_EAGAIN       8835
+#define SF_ERROR_EINPROGRESS  8836
 #define SF_ERROR_EOVERFLOW    8884
 #define SF_ERROR_EOPNOTSUPP   8895
 #define SF_ERROR_ENODATA      8861
diff --git a/src/sf_util.c b/src/sf_util.c
index 9c04db6..db82a8b 100644
--- a/src/sf_util.c
+++ b/src/sf_util.c
@@ -331,6 +331,8 @@ const char *sf_strerror(const int errnum)
             return STRERROR(EINVAL);
         case SF_ERROR_EAGAIN:
             return STRERROR(EAGAIN);
+        case SF_ERROR_EINPROGRESS:
+            return STRERROR(EINPROGRESS);
         case SF_ERROR_EOVERFLOW:
             return STRERROR(EOVERFLOW);
         case SF_ERROR_ENODATA:
diff --git a/src/sf_util.h b/src/sf_util.h
index 164f2ce..5f7747b 100644
--- a/src/sf_util.h
+++ b/src/sf_util.h
@@ -117,6 +117,8 @@ static inline int sf_unify_errno(const int errnum)
             return SF_ERROR_EINVAL;
         case EAGAIN:
             return SF_ERROR_EAGAIN;
+        case EINPROGRESS:
+            return SF_ERROR_EINPROGRESS;
         case EOVERFLOW:
             return SF_ERROR_EOVERFLOW;
         case EOPNOTSUPP:
@@ -141,6 +143,8 @@ static inline int sf_localize_errno(int errnum)
             return EINVAL;
         case SF_ERROR_EAGAIN:
             return EAGAIN;
+        case SF_ERROR_EINPROGRESS:
+            return EINPROGRESS;
         case SF_ERROR_EOVERFLOW:
             return EOVERFLOW;
         case SF_ERROR_EOPNOTSUPP: