diff --git a/src/gallium/auxiliary/util/u_surface.c b/src/gallium/auxiliary/util/u_surface.c
index d0e94f2db2b..11b16e6f229 100644
--- a/src/gallium/auxiliary/util/u_surface.c
+++ b/src/gallium/auxiliary/util/u_surface.c
@@ -42,6 +42,7 @@
 #include "util/u_surface.h"
 #include "util/u_pack_color.h"
 #include "util/u_memset.h"
+#include "util/log.h"
 
 /**
  * Initialize a pipe_surface object.  'view' is considered to have
@@ -294,8 +295,8 @@ util_resource_copy_region(struct pipe_context *pipe,
                                    src_level,
                                    PIPE_MAP_READ,
                                    &src_box, &src_trans);
-      assert(src_map);
       if (!src_map) {
+         mesa_loge("util_resource_copy_region: mapping src-buffer failed");
          goto no_src_map_buf;
       }
 
@@ -305,8 +306,8 @@ util_resource_copy_region(struct pipe_context *pipe,
                                    PIPE_MAP_WRITE |
                                    PIPE_MAP_DISCARD_RANGE, &dst_box,
                                    &dst_trans);
-      assert(dst_map);
       if (!dst_map) {
+         mesa_loge("util_resource_copy_region: mapping dst-buffer failed");
          goto no_dst_map_buf;
       }
 
@@ -325,8 +326,8 @@ util_resource_copy_region(struct pipe_context *pipe,
                                    src_level,
                                    PIPE_MAP_READ,
                                    &src_box, &src_trans);
-      assert(src_map);
       if (!src_map) {
+         mesa_loge("util_resource_copy_region: mapping src-texture failed");
          goto no_src_map;
       }
 
@@ -336,8 +337,8 @@ util_resource_copy_region(struct pipe_context *pipe,
                                    PIPE_MAP_WRITE |
                                    PIPE_MAP_DISCARD_RANGE, &dst_box,
                                    &dst_trans);
-      assert(dst_map);
       if (!dst_map) {
+         mesa_loge("util_resource_copy_region: mapping dst-texture failed");
          goto no_dst_map;
       }