diff --git a/.github/workflows/ruby.yml b/.github/workflows/ruby.yml
index b5732e1..98954cf 100644
--- a/.github/workflows/ruby.yml
+++ b/.github/workflows/ruby.yml
@@ -18,7 +18,7 @@ permissions:
 
 jobs:
   test:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-24.04
     strategy:
       matrix:
         ruby-version: 
@@ -32,9 +32,8 @@ jobs:
         - '2.7'
         - '3.0'
         - '3.1'
-        - jruby-9.1.17.0
-        - jruby-9.2.21.0
-        - jruby-9.3.6.0
+        - jruby-9.4.7.0
+        - jruby-10.0.2.0
 
     steps:
     - uses: actions/checkout@v3
diff --git a/ext/ios_parser/c_lexer/lexer.c b/ext/ios_parser/c_lexer/lexer.c
index 3c056c7..d5601e8 100644
--- a/ext/ios_parser/c_lexer/lexer.c
+++ b/ext/ios_parser/c_lexer/lexer.c
@@ -38,10 +38,10 @@ typedef struct LexInfo LexInfo;
 #define IS_SPACE(C)     C == ' ' || C == '\t' || C == '\r'
 #define IS_NEWLINE(C)   C == '\n'
 #define IS_COMMENT(C)   C == '!'
-#define IS_DIGIT(C)     '0' <= C && C <= '9'
+#define IS_DIGIT(C)     (('0' <= C) && (C <= '9'))
 #define IS_DOT(C)       C == '.'
 #define IS_DECIMAL(C)   IS_DIGIT(C) || IS_DOT(C)
-#define IS_LETTER(C)    'a' <= C && C <= 'z' || 'A' <= C && C <= 'Z'
+#define IS_LETTER(C)    (('a' <= C) && (C <= 'z')) || (('A' <= C) && (C <= 'Z'))
 #define IS_PUNCT(C)     strchr("-+$:/,()|*#=<>!\"\\&@;%~{}'\"?[]_^`", C)
 #define IS_WORD(C)      IS_DECIMAL(C) || IS_LETTER(C) || IS_PUNCT(C)
 #define IS_LEAD_ZERO(C) C == '0'
@@ -201,7 +201,7 @@ static VALUE allocate(VALUE klass) {
     return Data_Wrap_Struct(klass, mark, deallocate, lex);
 }
 
-static VALUE initialize(VALUE self, VALUE input_text) {
+static VALUE initialize(VALUE self) {
     LexInfo *lex;
     Data_Get_Struct(self, LexInfo, lex);
 
@@ -405,7 +405,7 @@ static void start_certificate(LexInfo *lex) {
 
 int is_banner_end_char(LexInfo *lex) {
     return CURRENT_CHAR(lex) == lex->banner_delimiter &&
-        (0 < lex->pos && '\n' == lex->text[lex->pos - 1] ||
+        ((0 < lex->pos && '\n' == lex->text[lex->pos - 1]) ||
          '\n' == lex->text[lex->pos + 1]);
 }
 
diff --git a/lib/ios_parser/version.rb b/lib/ios_parser/version.rb
index 658d7ad..7c2b07b 100644
--- a/lib/ios_parser/version.rb
+++ b/lib/ios_parser/version.rb
@@ -1,7 +1,7 @@
 module IOSParser
   class << self
     def version
-      '0.9.0'
+      '0.9.1'
     end
   end
 end