diff --git a/include/ruby/encoding.h b/include/ruby/encoding.h
index 28a89765f3..49ec29ac86 100644
--- a/include/ruby/encoding.h
+++ b/include/ruby/encoding.h
@@ -53,7 +53,7 @@
 				   (RBASIC(obj)->flags & ~ENC_CODERANGE_MASK) | (cr))
 #define ENC_CODERANGE_CLEAR(obj) ENC_CODERANGE_SET(obj,0)
 
-/* assumed ASCII compatiblity */
+/* assumed ASCII compatibility */
 #define ENC_CODERANGE_AND(a, b) \
     (a == ENC_CODERANGE_7BIT ? b : \
      a == ENC_CODERANGE_VALID ? (b == ENC_CODERANGE_7BIT ? ENC_CODERANGE_VALID : b) : \
diff --git a/include/ruby/ruby.h b/include/ruby/ruby.h
index e7ce62700c..d8ae11b204 100644
--- a/include/ruby/ruby.h
+++ b/include/ruby/ruby.h
@@ -265,7 +265,7 @@ VALUE rb_ull2inum(unsigned LONG_LONG);
 #define ID2SYM(x) (((VALUE)(x)<<RUBY_SPECIAL_SHIFT)|SYMBOL_FLAG)
 #define SYM2ID(x) RSHIFT((unsigned long)x,RUBY_SPECIAL_SHIFT)
 
-/* special contants - i.e. non-zero and non-fixnum constants */
+/* special constants - i.e. non-zero and non-fixnum constants */
 enum ruby_special_consts {
     RUBY_Qfalse = 0,
     RUBY_Qtrue  = 2,