diff --git a/src/eval.c b/src/eval.c
index 1e2a041..d4e3b9e 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -115,6 +115,8 @@
 static char *e_float_as_string = N_("E806: using Float as a String");
 #endif
 
+#define NAMESPACE_CHAR	(char_u *)"abglstvw"
+
 static dictitem_T	globvars_var;		/* variable used for g: */
 #define globvarht globvardict.dv_hashtab
 
@@ -20666,7 +20668,17 @@
 
     /* Find the end of the name. */
     for (p = *arg; eval_isnamec(*p); ++p)
-	;
+    {
+	if (*p == ':')
+	{
+	    /* "s:" is start of "s:var", but "n:" is not and can be used in
+	     * slice "[n:]".  Also "xx:" is not a namespace. */
+	    len = (int)(p - *arg);
+	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, **arg) == NULL)
+		    || len > 1)
+		break;
+	}
+    }
     if (p == *arg)	    /* no name found */
 	return 0;
 
@@ -20766,6 +20778,7 @@
     int		mb_nest = 0;
     int		br_nest = 0;
     char_u	*p;
+    int		len;
 
     if (expr_start != NULL)
     {
@@ -20801,6 +20814,15 @@
 	    if (*p == NUL)
 		break;
 	}
+	else if (br_nest == 0 && mb_nest == 0 && *p == ':')
+	{
+	    /* "s:" is start of "s:var", but "n:" is not and can be used in
+	     * slice "[n:]".  Also "xx:" is not a namespace. */
+	    len = (int)(p - arg);
+	    if ((len == 1 && vim_strchr(NAMESPACE_CHAR, *arg) == NULL)
+		    || len > 1)
+		break;
+	}
 
 	if (mb_nest == 0)
 	{
diff --git a/src/testdir/test_eval.in b/src/testdir/test_eval.in
index 087e609..84f26ba 100644
--- a/src/testdir/test_eval.in
+++ b/src/testdir/test_eval.in
@@ -218,6 +218,24 @@
 0:call setpos('.', sp)
 jyl:$put
 :"
+:" substring and variable name
+:let str = 'abcdef'
+:let n = 3
+:$put =str[n:]
+:$put =str[:n]
+:$put =str[n:n]
+:unlet n
+:let nn = 3
+:$put =str[nn:]
+:$put =str[:nn]
+:$put =str[nn:nn]
+:unlet nn
+:let b:nn = 4
+:$put =str[b:nn:]
+:$put =str[:b:nn]
+:$put =str[b:nn:b:nn]
+:unlet b:nn
+:"
 :/^start:/+1,$wq! test.out
 :" vim: et ts=4 isk-=\: fmr=???,???
 :call getchar()
diff --git a/src/testdir/test_eval.ok b/src/testdir/test_eval.ok
index cda425c..9ffa541 100644
--- a/src/testdir/test_eval.ok
+++ b/src/testdir/test_eval.ok
Binary files differ
diff --git a/src/version.c b/src/version.c
index baecfc7..f74281d 100644
--- a/src/version.c
+++ b/src/version.c
@@ -742,6 +742,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1105,
+/**/
     1104,
 /**/
     1103,