diff --git a/configure.in b/configure.in
index 57d69af62..91dcccf87 100644
--- a/configure.in
+++ b/configure.in
@@ -437,7 +437,7 @@ fi
 
 MUTTER_LIBS="$MUTTER_LIBS $XSYNC_LIBS $RANDR_LIBS $SHAPE_LIBS $X_LIBS $X_PRE_LIBS -lX11 $X_EXTRA_LIBS -lm"
 MUTTER_MESSAGE_LIBS="$MUTTER_MESSAGE_LIBS $X_LIBS $X_PRE_LIBS -lX11 $X_EXTRA_LIBS"
-MUTTER_WINDOW_DEMO_LIBS="$MUTTER_WINDOW_DEMO_LIBS $X_LIBS $X_PRE_LIBS -lX11 $X_EXTRA_LIBS"
+MUTTER_WINDOW_DEMO_LIBS="$MUTTER_WINDOW_DEMO_LIBS $X_LIBS $X_PRE_LIBS -lX11 $X_EXTRA_LIBS -lm"
 MUTTER_PROPS_LIBS="$MUTTER_PROPS_LIBS $X_LIBS $X_PRE_LIBS -lX11 $X_EXTRA_LIBS"
 
 found_sm=no