diff --git a/src/glsl/ast.h b/src/glsl/ast.h
index 78d24ae069d..816d5fccbbc 100644
--- a/src/glsl/ast.h
+++ b/src/glsl/ast.h
@@ -467,6 +467,11 @@ struct ast_type_qualifier {
     */
    bool has_storage() const;
 
+   /**
+    * Return whether an auxiliary storage qualifier is present.
+    */
+   bool has_auxiliary_storage() const;
+
    /**
     * \brief Return string representation of interpolation qualifier.
     *
diff --git a/src/glsl/ast_type.cpp b/src/glsl/ast_type.cpp
index 2e55b76762b..4cbb835ee1e 100644
--- a/src/glsl/ast_type.cpp
+++ b/src/glsl/ast_type.cpp
@@ -85,6 +85,12 @@ ast_type_qualifier::has_storage() const
           || this->flags.q.uniform;
 }
 
+bool
+ast_type_qualifier::has_auxiliary_storage() const
+{
+   return this->flags.q.centroid;
+}
+
 const char*
 ast_type_qualifier::interpolation_string() const
 {