diff --git a/EXAMPLES/MATRIX_MARKET/arpackmm.sh b/EXAMPLES/MATRIX_MARKET/arpackmm.sh
index 3ee5818d..93db4dae 100755
--- a/EXAMPLES/MATRIX_MARKET/arpackmm.sh
+++ b/EXAMPLES/MATRIX_MARKET/arpackmm.sh
@@ -60,16 +60,18 @@ do
                     fi
                   fi
 
+                  # CAUTION: when running arpackmm, do NOT double-quote arguments (= do NOT preserve spaces).
+
                   # Run arpackmm: use --nbCV 6 and --maxIt 200 to ease convergence.
-                  ./arpackmm "$eigPb $genPb $magOpt $shiftRI $invert $tol $slv $rs $dsPrec $dsMat $extraGenPb" \
-                             --nbCV 6 --maxIt 200                                                              \
+                  ./arpackmm $eigPb $genPb $magOpt $shiftRI $invert $tol $slv $rs $dsPrec $dsMat $extraGenPb \
+                             --nbCV 6 --maxIt 200                                                            \
                              --verbose 3 --debug 3 &> arpackmm.run.log
                   tail arpackmm.run.log
 
                   # Run arpackmm: re-run with restart from slightly different starting point using shift.
-                  ./arpackmm "$eigPb $genPb $magOpt $shiftRI $invert $tol $slv $rs $dsPrec $dsMat $extraGenPb" \
-                             --nbCV 6 --maxIt 200                                                              \
-                             --restart "$shiftOpt"                                                             \
+                  ./arpackmm $eigPb $genPb $magOpt $shiftRI $invert $tol $slv $rs $dsPrec $dsMat $extraGenPb \
+                             --nbCV 6 --maxIt 200                                                            \
+                             --restart $shiftOpt                                                             \
                              --verbose 3 --debug 3 &> arpackmm.run.log
                   tail arpackmm.run.log
                   echo "========================================================================================"