diff --git a/pwgenerator/types.go b/pwgenerator/types.go
index 2dc6006..470e8df 100644
--- a/pwgenerator/types.go
+++ b/pwgenerator/types.go
@@ -50,7 +50,7 @@ type GenOpts struct {
 	// CountExtended specifies how many extended symbols (0x80 to 0xff) should be specified at a minimum.
 	CountExtended uint `json:"extended" toml:"extended" yaml:"Number of Extended Symbols" xml:"numXSymbols,attr"`
 	// DisabledChars includes characters that should NOT be included from the above selection options.
-	DisabledChars CharSet `json:"disabled_chars" toml:"disabled_chars" yaml:"Disabled CharSet" xml:"disabledChars"`
+	DisabledChars CharSet `json:"disabled_chars,omitempty" toml:"disabled_chars,omitempty" yaml:"Disabled CharSet,omitempty" xml:"disabledChars,omitempty"`
 	// LengthMin specifies how long (in characters/bytes) each password should be at minimum. Use 0 for no minimum.
 	LengthMin uint `json:"length_min" toml:"length_min" yaml:"Minimum Length" xml:"minLen,attr"`
 	/*