diff --git a/src/nfa/rdfa.cpp b/src/nfa/rdfa.cpp
index 077ff9ed..ae857b6a 100644
--- a/src/nfa/rdfa.cpp
+++ b/src/nfa/rdfa.cpp
@@ -33,10 +33,6 @@ namespace ue2 {
 // prevent weak vtables
 raw_dfa::~raw_dfa() {}
 
-u16 raw_dfa::getImplAlphaSize() const {
-    return alpha_size - N_SPECIAL_SYMBOL;
-}
-
 void raw_dfa::stripExtraEodReports(void) {
     /* if a state generates a given report as a normal accept - then it does
      * not also need to generate an eod report for it */
diff --git a/src/nfa/rdfa.h b/src/nfa/rdfa.h
index 0936fb15..6b994e4f 100644
--- a/src/nfa/rdfa.h
+++ b/src/nfa/rdfa.h
@@ -81,7 +81,7 @@ struct raw_dfa {
     explicit raw_dfa(nfa_kind k) : kind(k) {}
     virtual ~raw_dfa();
 
-    u16 getImplAlphaSize() const;
+    u16 getImplAlphaSize() const { return alpha_size - N_SPECIAL_SYMBOL; }
     virtual void stripExtraEodReports(void);
     bool hasEodReports(void) const;
 };