diff --git a/src/mesa/shader/shader_api.c b/src/mesa/shader/shader_api.c
index 92bf3ec..9c701b3 100644
--- a/src/mesa/shader/shader_api.c
+++ b/src/mesa/shader/shader_api.c
@@ -716,6 +716,15 @@ sizeof_glsl_type(GLenum type)
    case GL_INT:
    case GL_BOOL:
       return 1;
+   case GL_SAMPLER_1D:
+   case GL_SAMPLER_2D:
+   case GL_SAMPLER_3D:
+   case GL_SAMPLER_CUBE:
+   case GL_SAMPLER_1D_SHADOW:
+   case GL_SAMPLER_2D_SHADOW:
+   case GL_SAMPLER_2D_RECT_ARB:
+   case GL_SAMPLER_2D_RECT_SHADOW_ARB:
+     return 1;
    case GL_FLOAT_VEC2:
    case GL_INT_VEC2:
    case GL_BOOL_VEC2: