--- moderncv.cls	2015-07-23 19:23:42.487668400 +0200
+++ moderncv-1.5.1-patched.cls	2015-07-23 20:14:06.344643700 +0200
@@ -145,16 +145,17 @@
 \newif\if@displaypagenumbers\@displaypagenumberstrue
 \newcommand*{\nopagenumbers}{\@displaypagenumbersfalse}
 \AtEndPreamble{%
-  \AtBeginDocument{%
-    \if@displaypagenumbers%
-      \@ifundefined{r@lastpage}{}{%
+  \if@displaypagenumbers%
+	\AtEndDocument{\label{lastpage}}
+	\AtBeginDocument{%
+      \@ifundefined{r@lastpage}{\ClassWarning{moderncv}{LaTeX Warning: r@lastpage is undefined. Label:lastpage on last page is missing?}}{%
         \ifthenelse{\pageref{lastpage}>1}{%
           \newlength{\pagenumberwidth}%
           \settowidth{\pagenumberwidth}{\color{color2}\addressfont\itshape\strut\thepage/\pageref{lastpage}}%
           \fancypagestyle{plain}{%
             \fancyfoot[r]{\parbox[b]{\pagenumberwidth}{\color{color2}\pagenumberfont\strut\thepage/\pageref{lastpage}}}}% the parbox is required to ensure alignment with a possible center footer (e.g., as in the casual style)
-          \pagestyle{plain}}{}}%
-      \AtEndDocument{\label{lastpage}}\else\fi}}
+          \pagestyle{plain}}{}}}%
+  \else\fi}
 \pagestyle{plain}
 
 % reduced list spacing