diff --git a/src/asm/rgbasm.5 b/src/asm/rgbasm.5
index 7df0e3ab..f9fde8c1 100644
--- a/src/asm/rgbasm.5
+++ b/src/asm/rgbasm.5
@@ -1081,7 +1081,7 @@ The example below includes 256 bytes from data.bin, starting from byte 78.
 INCBIN "data.bin",78,256
 .Ed
 .Pp
-The length arugment is optional. If only the start position is specified, the bytes from the start position until the end of the file will be included.
+The length argument is optional. If only the start position is specified, the bytes from the start position until the end of the file will be included.
 .Ss Unions
 .Pp
 Unions allow multiple memory allocations to overlap, like unions in C.