diff --git a/src/rendering/gl/shaders/gl_shader.cpp b/src/rendering/gl/shaders/gl_shader.cpp
index 2d2ceda41..939faf557 100644
--- a/src/rendering/gl/shaders/gl_shader.cpp
+++ b/src/rendering/gl/shaders/gl_shader.cpp
@@ -392,7 +392,7 @@ bool FShader::Load(const char * name, const char * vert_prog_lump, const char *
 				// this looks like an old custom hardware shader.
 
 				// add ProcessMaterial function that calls the older ProcessTexel function
-				int pl_lump = Wads.CheckNumForFullName("shaders/glsl/func_defaultmat.fp");
+				int pl_lump = Wads.CheckNumForFullName("shaders/glsl/func_defaultmat.fp", 0);
 				if (pl_lump == -1) I_Error("Unable to load '%s'", "shaders/glsl/func_defaultmat.fp");
 				FMemLump pl_data = Wads.ReadLump(pl_lump);
 				fp_comb << "\n" << pl_data.GetString().GetChars();
@@ -418,7 +418,7 @@ bool FShader::Load(const char * name, const char * vert_prog_lump, const char *
 
 			if (pp_data.GetString().IndexOf("ProcessLight") < 0)
 			{
-				int pl_lump = Wads.CheckNumForFullName("shaders/glsl/func_defaultlight.fp");
+				int pl_lump = Wads.CheckNumForFullName("shaders/glsl/func_defaultlight.fp", 0);
 				if (pl_lump == -1) I_Error("Unable to load '%s'", "shaders/glsl/func_defaultlight.fp");
 				FMemLump pl_data = Wads.ReadLump(pl_lump);
 				fp_comb << "\n" << pl_data.GetString().GetChars();
@@ -433,7 +433,7 @@ bool FShader::Load(const char * name, const char * vert_prog_lump, const char *
 
 	if (light_fragprog)
 	{
-		int pp_lump = Wads.CheckNumForFullName(light_fragprog);
+		int pp_lump = Wads.CheckNumForFullName(light_fragprog, 0);
 		if (pp_lump == -1) I_Error("Unable to load '%s'", light_fragprog);
 		FMemLump pp_data = Wads.ReadLump(pp_lump);
 		fp_comb << pp_data.GetString().GetChars() << "\n";