diff --git a/src/clinfo_ext.h b/src/clinfo_ext.h
index bcd2ae57a448e1a22d6e9ded0335a95151db2472..52bac52dc737a6e6373e939a887aff860af2d398 100644
--- a/src/clinfo_ext.h
+++ b/src/clinfo_ext.h
@@ -49,6 +49,7 @@
 #define CL_DEVICE_ATTRIBUTE_ASYNC_ENGINE_COUNT_NV	0x4007
 #define CL_DEVICE_PCI_BUS_ID_NV				0x4008
 #define CL_DEVICE_PCI_SLOT_ID_NV			0x4009
+/* https://github.com/pocl/pocl/pull/910 */
 #define CL_DEVICE_PCI_DOMAIN_ID_NV          0x4010
 
 /* cl_ext_atomic_counters_{32,64} */
diff --git a/src/pyopencl_ext.h b/src/pyopencl_ext.h
index ef49b6b2dd224ed894d1a30d90f9bcf55c2b9555..a70b0df35bb2f24db00dcdfd24ce22aac069a14a 100644
--- a/src/pyopencl_ext.h
+++ b/src/pyopencl_ext.h
@@ -50,6 +50,7 @@ typedef union
 #endif
 
 #ifndef CL_DEVICE_PCI_DOMAIN_ID_NV
+/* https://github.com/pocl/pocl/pull/910 */
 #define CL_DEVICE_PCI_DOMAIN_ID_NV                      0x4010
 #endif