diff --git a/fpu/softfloat-parts.c.inc b/fpu/softfloat-parts.c.inc
index b8563cd2df..cc8c2c3aee 100644
--- a/fpu/softfloat-parts.c.inc
+++ b/fpu/softfloat-parts.c.inc
@@ -869,7 +869,7 @@ static void partsN(sqrt)(FloatPartsN *a, float_status *status,
     return;
 
  d_nan:
-    float_raise(float_flag_invalid, status);
+    float_raise(float_flag_invalid | float_flag_invalid_sqrt, status);
     parts_default_nan(a, status);
 }
 
diff --git a/include/fpu/softfloat-types.h b/include/fpu/softfloat-types.h
index 5a9671e564..33224b5f22 100644
--- a/include/fpu/softfloat-types.h
+++ b/include/fpu/softfloat-types.h
@@ -156,6 +156,7 @@ enum {
     float_flag_invalid_imz     = 0x0100,  /* inf * 0 */
     float_flag_invalid_idi     = 0x0200,  /* inf / inf */
     float_flag_invalid_zdz     = 0x0400,  /* 0 / 0 */
+    float_flag_invalid_sqrt    = 0x0800,  /* sqrt(-x) */
 };
 
 /*