diff --git a/src/mesa/main/texcompress_s3tc.c b/src/mesa/main/texcompress_s3tc.c
index 5f41320a67f..d489b2b783d 100644
--- a/src/mesa/main/texcompress_s3tc.c
+++ b/src/mesa/main/texcompress_s3tc.c
@@ -40,6 +40,7 @@
 #include "texstore.h"
 #include "format_unpack.h"
 #include "util/format_srgb.h"
+#include "util/format/u_format_s3tc.h"
 
 
 /**
@@ -382,3 +383,49 @@ _mesa_get_dxt_fetch_func(mesa_format format)
       return NULL;
    }
 }
+
+extern void
+_mesa_unpack_s3tc(uint8_t *dst_row,
+                  unsigned dst_stride,
+                  const uint8_t *src_row,
+                  unsigned src_stride,
+                  unsigned src_width,
+                  unsigned src_height,
+                  mesa_format format)
+{
+   /* We treat sRGB formats as RGB, because we're unpacking to another sRGB
+    * format.
+    */
+   switch (format) {
+   case MESA_FORMAT_RGB_DXT1:
+   case MESA_FORMAT_SRGB_DXT1:
+      util_format_dxt1_rgb_unpack_rgba_8unorm(dst_row, dst_stride,
+                                              src_row, src_stride,
+                                              src_width, src_height);
+      break;
+
+   case MESA_FORMAT_RGBA_DXT1:
+   case MESA_FORMAT_SRGBA_DXT1:
+      util_format_dxt1_rgba_unpack_rgba_8unorm(dst_row, dst_stride,
+                                               src_row, src_stride,
+                                               src_width, src_height);
+      break;
+
+   case MESA_FORMAT_RGBA_DXT3:
+   case MESA_FORMAT_SRGBA_DXT3:
+      util_format_dxt3_rgba_unpack_rgba_8unorm(dst_row, dst_stride,
+                                               src_row, src_stride,
+                                               src_width, src_height);
+      break;
+
+   case MESA_FORMAT_RGBA_DXT5:
+   case MESA_FORMAT_SRGBA_DXT5:
+      util_format_dxt5_rgba_unpack_rgba_8unorm(dst_row, dst_stride,
+                                               src_row, src_stride,
+                                               src_width, src_height);
+      break;
+
+   default:
+      unreachable("unexpected format");
+   }
+}
diff --git a/src/mesa/main/texcompress_s3tc.h b/src/mesa/main/texcompress_s3tc.h
index 0dbb5fc5371..833a397f392 100644
--- a/src/mesa/main/texcompress_s3tc.h
+++ b/src/mesa/main/texcompress_s3tc.h
@@ -47,5 +47,13 @@ _mesa_texstore_rgba_dxt5(TEXSTORE_PARAMS);
 extern compressed_fetch_func
 _mesa_get_dxt_fetch_func(mesa_format format);
 
+extern void
+_mesa_unpack_s3tc(uint8_t *dst_row,
+                  unsigned dst_stride,
+                  const uint8_t *src_row,
+                  unsigned src_stride,
+                  unsigned src_width,
+                  unsigned src_height,
+                  mesa_format format);
 
 #endif /* TEXCOMPRESS_S3TC_H */