diff --git a/IPython/nbconvert/templates/latex/latex_base.tplx b/IPython/nbconvert/templates/latex/latex_base.tplx
index 171795d..3a3e715 100644
--- a/IPython/nbconvert/templates/latex/latex_base.tplx
+++ b/IPython/nbconvert/templates/latex/latex_base.tplx
@@ -158,7 +158,7 @@ This template does not define a docclass, the inheriting class must define this.
     ((* elif cell.level == 6 -*))
         ((* block h6 -*))\\*\textit((* endblock h6 -*))
     ((*- endif -*))
-    {((( cell.source | citation2latex | escape_latex )))}
+    {((( cell.source | replace('\n', ' ') | citation2latex | escape_latex )))}
 
 ((* endblock headingcell *))