diff --git a/Source/kwsys/System.c b/Source/kwsys/System.c
index 33e114928..288513fb4 100644
--- a/Source/kwsys/System.c
+++ b/Source/kwsys/System.c
@@ -59,7 +59,7 @@ static int kwsysSystem_Shell__CharIsWhitespace(char c)
 /*--------------------------------------------------------------------------*/
 static int kwsysSystem_Shell__CharNeedsQuotesOnUnix(char c)
 {
-  return ((c == '\'') || (c == '`') || (c == ';') ||
+  return ((c == '\'') || (c == '`') || (c == ';') || (c == '#') ||
           (c == '&') || (c == '$') || (c == '(') || (c == ')'));
 }
 
diff --git a/Tests/CustomCommand/CMakeLists.txt b/Tests/CustomCommand/CMakeLists.txt
index 768503151..602f69b79 100644
--- a/Tests/CustomCommand/CMakeLists.txt
+++ b/Tests/CustomCommand/CMakeLists.txt
@@ -190,6 +190,8 @@ SET(CHECK_ARGS
   amper&sand
   @two-ats@
   one@at
+  "#two-pounds#"
+  "one#pound"
   "c:/posix/path/with space"
   "c:\\windows\\path\\with space"
   "'single quotes with space'"
@@ -209,6 +211,8 @@ SET(CHECK_ARGS
   "amper&sand with space"
   "@two-ats@ with space"
   "one@at with space"
+  "#two-pounds# with space"
+  "one#pound with space"
   )
 FOREACH(arg ${CHECK_ARGS})
   SET(ARG "${arg}")