diff --git a/regex/compile.go b/regex/compile.go
index 86c552b..ba59c9f 100644
--- a/regex/compile.go
+++ b/regex/compile.go
@@ -867,7 +867,7 @@ func thompson(re []postfixNode) (Reg, error) {
 			stateToAdd.isEmpty = false
 			if c.nodetype == assertionNode {
 				stateToAdd.isEmpty = true                 // This is a little weird. A lookaround has the 'isEmpty' flag set, even though it _isn't_ empty (the contents are the regex). But, there's so much error-checking that relies on this flag that it's better to keep it this way.
-				stateToAdd.content = newContents(EPSILON) // Ideally, an assertion shouldn't have any content, since it doesn't say anything about the content of string
+				stateToAdd.content = newContents(epsilon) // Ideally, an assertion shouldn't have any content, since it doesn't say anything about the content of string
 				if c.lookaroundDir == 0 || c.lookaroundSign == 0 {
 					switch c.contents[0] {
 					case '^':
@@ -920,7 +920,7 @@ func thompson(re []postfixNode) (Reg, error) {
 		if c.nodetype == lparenNode || c.nodetype == rparenNode {
 			s := &nfaState{}
 			s.assert = noneAssert
-			s.content = newContents(EPSILON)
+			s.content = newContents(epsilon)
 			s.isEmpty = true
 			s.output = make([]*nfaState, 0)
 			s.output = append(s.output, s)
diff --git a/regex/matching.go b/regex/matching.go
index 61dca15..559b88e 100644
--- a/regex/matching.go
+++ b/regex/matching.go
@@ -63,8 +63,8 @@ func (g Group) isValid() bool {
 // If a state begins or ends a capturing group, its 'thread' is updated to contain the correct index.
 func takeZeroState(states []*nfaState, numGroups int, idx int) (rtv []*nfaState, isZero bool) {
 	for _, state := range states {
-		if len(state.transitions[EPSILON]) > 0 {
-			for _, s := range state.transitions[EPSILON] {
+		if len(state.transitions[epsilon]) > 0 {
+			for _, s := range state.transitions[epsilon] {
 				if s.threadGroups == nil {
 					s.threadGroups = newMatch(numGroups + 1)
 				}
@@ -78,7 +78,7 @@ func takeZeroState(states []*nfaState, numGroups int, idx int) (rtv []*nfaState,
 					//					closeParenGroups = append(closeParenGroups, s.groupNum)
 				}
 			}
-			rtv = append(rtv, state.transitions[EPSILON]...)
+			rtv = append(rtv, state.transitions[epsilon]...)
 		}
 	}
 	for _, state := range rtv {