2 files changed, 6 insertions, 3 deletions

diff --git a/usr.bin/truncate/truncate.1 b/usr.bin/truncate/truncate.1
index 6c1d65784c29..9449939ec67d 100644
--- a/usr.bin/truncate/truncate.1
+++ b/usr.bin/truncate/truncate.1
@@ -39,7 +39,7 @@
 .Sm off
 .Op Cm + | -
 .Ar size
-.Op Cm K | M | G
+.Op Cm K | k | M | m | G | g
 .Sm on
 .Xc
 .Ek
@@ -71,7 +71,7 @@ Truncate files to the length of the file
 .Sm off
 .Op Cm + | -
 .Ar size
-.Op Cm K | M | G
+.Op Cm K | k | M | m | G | g
 .Sm on
 .Xc
 If the
@@ -97,7 +97,7 @@ argument may be suffixed with one of
 .Cm M
 or
 .Cm G
-to indicate a multiple of
+(either upper or lower case) to indicate a multiple of
 Kilobytes, Megabytes or Gigabytes
 respectively.
 .El
diff --git a/usr.bin/truncate/truncate.c b/usr.bin/truncate/truncate.c
index 2901ae9c8756..60119356c9f0 100644
--- a/usr.bin/truncate/truncate.c
+++ b/usr.bin/truncate/truncate.c
@@ -177,12 +177,15 @@ parselength(char *ls, off_t *sz)
 
 	switch (*ls) {
 	case 'G':
+	case 'g':
 		oflow = length * 1024;
 		ASSIGN_CHK_OFLOW(oflow, length);
 	case 'M':
+	case 'm':
 		oflow = length * 1024;
 		ASSIGN_CHK_OFLOW(oflow, length);
 	case 'K':
+	case 'k':
 		if (ls[1] != '\0')
 			return -1;
 		oflow = length * 1024;