diff --git a/src/microsoft/compiler/dxil_signature.c b/src/microsoft/compiler/dxil_signature.c
index 9718a42ea5a..9cd94b9ea8a 100644
--- a/src/microsoft/compiler/dxil_signature.c
+++ b/src/microsoft/compiler/dxil_signature.c
@@ -62,7 +62,7 @@ get_interpolation(nir_variable *var)
       case INTERP_MODE_NONE: return DXIL_INTERP_LINEAR_CENTROID;
       case INTERP_MODE_FLAT: return DXIL_INTERP_CONSTANT;
       case INTERP_MODE_NOPERSPECTIVE: return DXIL_INTERP_LINEAR_NOPERSPECTIVE_CENTROID;
-      case INTERP_MODE_SMOOTH: DXIL_INTERP_LINEAR_CENTROID;
+      case INTERP_MODE_SMOOTH: return DXIL_INTERP_LINEAR_CENTROID;
 
       }
    } else {