diff --git a/regex/src/main/java/org/pcre4j/regex/Matcher.java b/regex/src/main/java/org/pcre4j/regex/Matcher.java
index f1e6216..fe8e13e 100644
--- a/regex/src/main/java/org/pcre4j/regex/Matcher.java
+++ b/regex/src/main/java/org/pcre4j/regex/Matcher.java
@@ -84,7 +84,7 @@ public class Matcher implements java.util.regex.MatchResult {
     /* package-private */ Matcher(Pattern pattern, CharSequence input) {
         this.pattern = pattern;
         this.matchContext = new Pcre2MatchContext(pattern.code.api(), null);
-        if (pattern.code instanceof Pcre2JitCode) {
+        if (pattern.code.jitSize() > 0) {
             this.jitStack = new Pcre2JitStack(pattern.code.api(), JIT_STACK_START_SIZE, JIT_STACK_MAX_SIZE, null);
             this.matchContext.assignJitStack(jitStack);
         } else {
@@ -557,7 +557,7 @@ public Matcher usePattern(Pattern newPattern) {
 
         this.pattern = newPattern;
         this.matchContext = new Pcre2MatchContext(pattern.code.api(), null);
-        if (pattern.code instanceof Pcre2JitCode) {
+        if (pattern.code.jitSize() > 0) {
             this.jitStack = new Pcre2JitStack(pattern.code.api(), JIT_STACK_START_SIZE, JIT_STACK_MAX_SIZE, null);
             this.matchContext.assignJitStack(jitStack);
         } else {