diff --git a/src/cvars.cpp b/src/cvars.cpp
index 7a232def2..f3fc0695c 100644
--- a/src/cvars.cpp
+++ b/src/cvars.cpp
@@ -1469,11 +1469,11 @@ consvar_t cv_voice_allowservervoice = NetVar("voice_allowservervoice", "Off")
 #ifdef HWRENDER
 	consvar_t cv_fovchange = OpenGL("gr_fovchange", "Off").on_off();
 
-	extern CV_PossibleValue_t glshaders_cons_t[];
+	extern "C" CV_PossibleValue_t glshaders_cons_t[];
 	consvar_t cv_glallowshaders = OpenGL("gr_allowclientshaders", "On").on_off().network().dont_save();
 	consvar_t cv_glshaders = OpenGL("gr_shaders", "On").values(glshaders_cons_t);
 
-	extern CV_PossibleValue_t glanisotropicmode_cons_t[];
+	extern "C" CV_PossibleValue_t glanisotropicmode_cons_t[];
 	extern "C" void CV_glanisotropic_OnChange(void);
 	consvar_t cv_glanisotropicmode = OpenGL("gr_anisotropicmode", "1").values(glanisotropicmode_cons_t).onchange(CV_glanisotropic_OnChange);
 
@@ -1486,7 +1486,7 @@ consvar_t cv_voice_allowservervoice = NetVar("voice_allowservervoice", "Off")
 		consvar_t cv_glstaticlighting  = OpenGL("gr_staticlighting", "On").on_off();
 #endif
 
-	extern CV_PossibleValue_t glfiltermode_cons_t[];
+	extern "C" CV_PossibleValue_t glfiltermode_cons_t[];
 	extern "C" void CV_glfiltermode_OnChange(void);
 	consvar_t cv_glfiltermode = OpenGL("gr_filtermode", "Nearest").values(glfiltermode_cons_t).onchange(CV_glfiltermode_OnChange);
 
diff --git a/src/hardware/hw_main.cpp b/src/hardware/hw_main.cpp
index 7867a85d8..3b2bdfac9 100644
--- a/src/hardware/hw_main.cpp
+++ b/src/hardware/hw_main.cpp
@@ -6057,8 +6057,10 @@ void HWR_LoadLevel(void)
 //                                                         3D ENGINE COMMANDS
 // ==========================================================================
 
+extern "C" CV_PossibleValue_t glshaders_cons_t[];
 CV_PossibleValue_t glshaders_cons_t[] = {{HWD_SHADEROPTION_OFF, "Off"}, {HWD_SHADEROPTION_ON, "On"}, {HWD_SHADEROPTION_NOCUSTOM, "Ignore custom shaders"}, {0, NULL}};
 
+extern "C" CV_PossibleValue_t glfiltermode_cons_t[];
 CV_PossibleValue_t glfiltermode_cons_t[]= {{HWD_SET_TEXTUREFILTER_POINTSAMPLED, "Nearest"},
 	{HWD_SET_TEXTUREFILTER_BILINEAR, "Bilinear"}, {HWD_SET_TEXTUREFILTER_TRILINEAR, "Trilinear"},
 	{HWD_SET_TEXTUREFILTER_MIXED1, "Linear_Nearest"},
@@ -6066,6 +6068,7 @@ CV_PossibleValue_t glfiltermode_cons_t[]= {{HWD_SET_TEXTUREFILTER_POINTSAMPLED,
 	{HWD_SET_TEXTUREFILTER_MIXED3, "Nearest_Mipmap"},
 	{0, NULL}};
 
+extern "C" CV_PossibleValue_t glanisotropicmode_cons_t[];
 CV_PossibleValue_t glanisotropicmode_cons_t[] = {{1, "MIN"}, {16, "MAX"}, {0, NULL}};
 
 extern "C" void CV_glfiltermode_OnChange(void);
@@ -6082,11 +6085,12 @@ void CV_glanisotropic_OnChange(void)
 		HWD.pfnSetSpecialState(HWD_SET_TEXTUREANISOTROPICMODE, cv_glanisotropicmode.value);
 }
 
+extern "C" struct CVarList *cvlist_opengl;
+
 //added by Hurdler: console varibale that are saved
 void HWR_AddCommands(void)
 {
 	{
-		extern struct CVarList *cvlist_opengl;
 		CV_RegisterList(cvlist_opengl);
 	}
 }