diff --git a/sphinx/texinputs/sphinxlatexshadowbox.sty b/sphinx/texinputs/sphinxlatexshadowbox.sty
index 147e266a5f9..555ede26f15 100644
--- a/sphinx/texinputs/sphinxlatexshadowbox.sty
+++ b/sphinx/texinputs/sphinxlatexshadowbox.sty
@@ -150,7 +150,7 @@
 
 % 8.1.0
 \newenvironment{sphinxtopic}
-               {\begin{sphinxShadowBox}}{\end{sphinxShadowBox}}
+               {\begin{sphinxShadowBox}[topic]}{\end{sphinxShadowBox}}
 \newenvironment{sphinxcontents}
                {\begin{sphinxShadowBox}[contents]}{\end{sphinxShadowBox}}
 % Arguably sphinxsidebar should rather use a wrapfig or similar environment