diff --git a/src/host_shaders/opengl_fragment_shader.frag b/src/host_shaders/opengl_fragment_shader.frag
index 2fd4146a..a78f42b8 100644
--- a/src/host_shaders/opengl_fragment_shader.frag
+++ b/src/host_shaders/opengl_fragment_shader.frag
@@ -32,7 +32,7 @@ uniform sampler1DArray u_tex_lighting_lut;
 uniform uint u_picaRegs[0x200 - 0x48];
 
 // Helper so that the implementation of u_pica_regs can be changed later
-uint readPicaReg(uint reg_addr) { return u_picaRegs[reg_addr - 0x48]; }
+uint readPicaReg(uint reg_addr) { return u_picaRegs[reg_addr - 0x48u]; }
 
 vec4 tevSources[16];
 vec4 tevNextPreviousBuffer;
@@ -414,4 +414,4 @@ void main() {
 				break;
 		}
 	}
-}
\ No newline at end of file
+}