diff --git a/src/mesa/main/framebuffer.c b/src/mesa/main/framebuffer.c
index af3c595..9bff9d4 100644
--- a/src/mesa/main/framebuffer.c
+++ b/src/mesa/main/framebuffer.c
@@ -878,6 +878,9 @@ _mesa_dest_buffer_exists(struct gl_context *ctx, GLenum format)
 GLenum
 _mesa_get_color_read_format(struct gl_context *ctx)
 {
+   if (ctx->ReadBuffer == NULL ||  ctx->ReadBuffer->_ColorReadBuffer == NULL)
+      return 0;
+
    const GLenum data_type = _mesa_get_format_datatype(
                                ctx->ReadBuffer->_ColorReadBuffer->Format);
 
@@ -902,6 +905,9 @@ _mesa_get_color_read_format(struct gl_context *ctx)
 GLenum
 _mesa_get_color_read_type(struct gl_context *ctx)
 {
+   if (ctx->ReadBuffer == NULL ||  ctx->ReadBuffer->_ColorReadBuffer == NULL)
+      return 0;
+
    const GLenum data_type = _mesa_get_format_datatype(
                                ctx->ReadBuffer->_ColorReadBuffer->Format);