diff --git a/src/mesa/main/formats.c b/src/mesa/main/formats.c
index 19489e84648..f48c782a022 100644
--- a/src/mesa/main/formats.c
+++ b/src/mesa/main/formats.c
@@ -655,6 +655,16 @@ _mesa_is_format_s3tc(mesa_format format)
 }
 
 
+/**
+ * Return TRUE if format is an RGTC compressed format.
+ */
+bool
+_mesa_is_format_rgtc(mesa_format format)
+{
+   return _mesa_get_format_layout(format) == MESA_FORMAT_LAYOUT_RGTC;
+}
+
+
 /**
  * Return TRUE if format is an BPTC compressed format.
  */
diff --git a/src/mesa/main/formats.h b/src/mesa/main/formats.h
index e8f91389b93..acc69c1654d 100644
--- a/src/mesa/main/formats.h
+++ b/src/mesa/main/formats.h
@@ -698,6 +698,9 @@ _mesa_is_format_astc_2d(mesa_format format);
 bool
 _mesa_is_format_s3tc(mesa_format format);
 
+bool
+_mesa_is_format_rgtc(mesa_format format);
+
 bool
 _mesa_is_format_bptc(mesa_format format);