diff --git a/src/common/rendering/gl/gl_shader.cpp b/src/common/rendering/gl/gl_shader.cpp
index 51a72318ee..601d7be451 100644
--- a/src/common/rendering/gl/gl_shader.cpp
+++ b/src/common/rendering/gl/gl_shader.cpp
@@ -626,6 +626,9 @@ bool FShader::Load(const char * name, const char * vert_prog_lump, const char *
 	int shadowmapindex = glGetUniformLocation(hShader, "ShadowMap");
 	if (shadowmapindex > 0) glUniform1i(shadowmapindex, 16);
 
+	int lightmapindex = glGetUniformLocation(hShader, "LightMap");
+	if (lightmapindex > 0) glUniform1i(lightmapindex, 17);
+
 	glUseProgram(0);
 	return linked;
 }