diff --git a/src/ex_getln.c b/src/ex_getln.c
index 22f35e1..8765ac5 100644
--- a/src/ex_getln.c
+++ b/src/ex_getln.c
@@ -293,11 +293,12 @@
 		// Skip over "substitute" to find the pattern separator.
 		for (p = cmd; ASCII_ISALPHA(*p); ++p)
 		    ;
-		if (*p != NUL
+		if (*skipwhite(p) != NUL
 			&& (STRNCMP(cmd, "substitute", p - cmd) == 0
 			    || STRNCMP(cmd, "global", p - cmd) == 0
 			    || STRNCMP(cmd, "vglobal", p - cmd) == 0))
 		{
+		    p = skipwhite(p);
 		    delim = *p++;
 		    end = skip_regexp(p, delim, p_magic, NULL);
 		    if (end > p || *end == delim)