diff --git a/src/r_data/gldefs.cpp b/src/r_data/gldefs.cpp
index be4645699..27bc58766 100644
--- a/src/r_data/gldefs.cpp
+++ b/src/r_data/gldefs.cpp
@@ -1266,26 +1266,29 @@ class GLDefsParser
 					}
 				}
 				sc.MustGetString();
-				bool okay = false;
-				for (int i = 0; i < MAX_CUSTOM_HW_SHADER_TEXTURES; i++)
+				if (tex)
 				{
-					if (!tex->CustomShaderTextures[i])
+					bool okay = false;
+					for (int i = 0; i < MAX_CUSTOM_HW_SHADER_TEXTURES; i++)
 					{
-						tex->CustomShaderTextures[i] = TexMan.FindTexture(sc.String, ETextureType::Any, FTextureManager::TEXMAN_TryAny);
 						if (!tex->CustomShaderTextures[i])
 						{
-							sc.ScriptError("Custom hardware shader texture '%s' not found in texture '%s'\n", sc.String, tex ? tex->Name.GetChars() : "(null)");
-						}
+							tex->CustomShaderTextures[i] = TexMan.FindTexture(sc.String, ETextureType::Any, FTextureManager::TEXMAN_TryAny);
+							if (!tex->CustomShaderTextures[i])
+							{
+								sc.ScriptError("Custom hardware shader texture '%s' not found in texture '%s'\n", sc.String, tex->Name.GetChars());
+							}
 
-						texNameList.Push(textureName);
-						texNameIndex.Push(i);
-						okay = true;
-						break;
+							texNameList.Push(textureName);
+							texNameIndex.Push(i);
+							okay = true;
+							break;
+						}
+					}
+					if (!okay)
+					{
+						sc.ScriptError("Error: out of texture units in texture '%s'", tex->Name.GetChars());
 					}
-				}
-				if (!okay)
-				{
-					sc.ScriptError("Error: out of texture units in texture '%s'", tex ? tex->Name.GetChars() : "(null)");
 				}
 			}
 			else if (sc.Compare("define"))