diff --git a/common/broxton/hw-gfx-gma-spll.ads b/common/broxton/hw-gfx-gma-spll.ads
index 571dde9..277a8c1 100644
--- a/common/broxton/hw-gfx-gma-spll.ads
+++ b/common/broxton/hw-gfx-gma-spll.ads
@@ -12,7 +12,7 @@
 -- GNU General Public License for more details.
 --
 
-package HW.GFX.GMA.SPLL is
+private package HW.GFX.GMA.SPLL is
 
    -- Just for a common interface with Haswell's DDI.
    -- There is no SPLL (no FDI) on Broxton.
diff --git a/common/haswell/hw-gfx-gma-spll.ads b/common/haswell/hw-gfx-gma-spll.ads
index 60222ed..bd1402c 100644
--- a/common/haswell/hw-gfx-gma-spll.ads
+++ b/common/haswell/hw-gfx-gma-spll.ads
@@ -12,7 +12,7 @@
 -- GNU General Public License for more details.
 --
 
-package HW.GFX.GMA.SPLL is
+private package HW.GFX.GMA.SPLL is
 
    procedure On;
 
diff --git a/common/skylake/hw-gfx-gma-spll.ads b/common/skylake/hw-gfx-gma-spll.ads
index 6b9dc01..7b038df 100644
--- a/common/skylake/hw-gfx-gma-spll.ads
+++ b/common/skylake/hw-gfx-gma-spll.ads
@@ -12,7 +12,7 @@
 -- GNU General Public License for more details.
 --
 
-package HW.GFX.GMA.SPLL is
+private package HW.GFX.GMA.SPLL is
 
    -- Just for a common interface with Haswell's DDI.
    -- There is no SPLL (no FDI) on Skylake.