diff --git a/Diagnostics/PlotMCMCDiag.cpp b/Diagnostics/PlotMCMCDiag.cpp
index 2dec34c52..fdd00bec2 100644
--- a/Diagnostics/PlotMCMCDiag.cpp
+++ b/Diagnostics/PlotMCMCDiag.cpp
@@ -183,11 +183,11 @@ void PlotAutoCorr(TString fname1, TString fname2, TString fname3, TString fname4
 
 int main(int argc, char *argv[]) {
   SetMaCh3LoggerFormat();
-  if (argc != 2)
+  if (argc < 2 || argc > 5)
   {
     MACH3LOG_ERROR("How to use: {} DiagMCMC_Output.root", argv[0]);
     MACH3LOG_ERROR("Up to 4 files");
-    throw MaCh3Exception(__FILE__ , __LINE__ );
+    throw MaCh3Exception(__FILE__ , __LINE__);
   }
 
   if(argc == 2) {
diff --git a/Diagnostics/ProcessMCMC.cpp b/Diagnostics/ProcessMCMC.cpp
index 2bfe25a16..0fe320a95 100644
--- a/Diagnostics/ProcessMCMC.cpp
+++ b/Diagnostics/ProcessMCMC.cpp
@@ -34,7 +34,7 @@ int main(int argc, char *argv[])
   nFiles = 0;
   if (argc != 3 && argc !=6 && argc != 8)
   {
-    MACH3LOG_ERROR("How to use: {}<Config> <MCMM_ND_Output.root>", argv[0]);
+    MACH3LOG_ERROR("How to use: {} <Config> <MCMM_ND_Output.root>", argv[0]);
     throw MaCh3Exception(__FILE__ , __LINE__ );
   }