diff --git a/cellprofiler_all-plates/Makefile b/cellprofiler_all-plates/Makefile
index 3af2fd6..7dbf5e7 100644
--- a/cellprofiler_all-plates/Makefile
+++ b/cellprofiler_all-plates/Makefile
@@ -1,3 +1,3 @@
 .PHONY : analyst
 analyst :
-	~/bin/cellprofiler-analyst all-plates.properties 2>&1 | tee cellprofiler-analyst-$(date -Isec).log
+	~/bin/cellprofiler-analyst all-plates.properties 2>&1 | tee cellprofiler-analyst-$$(date -Isec).log