diff --git string.c string.c
index deeed4a12a..b4db760647 100644
--- string.c
+++ string.c
@@ -8436,7 +8436,6 @@ rb_str_count(int argc, VALUE *argv, VALUE str)
     char *s, *send;
     int i;
     int ascompat;
-    size_t n = 0;
 
     rb_check_arity(argc, 1, UNLIMITED_ARGUMENTS);
 
@@ -8449,6 +8448,7 @@ rb_str_count(int argc, VALUE *argv, VALUE str)
             (ptstr = RSTRING_PTR(tstr),
              ONIGENC_IS_ALLOWED_REVERSE_MATCH(enc, (const unsigned char *)ptstr, (const unsigned char *)ptstr+1)) &&
             !is_broken_string(str)) {
+            int n = 0;
             int clen;
             unsigned char c = rb_enc_codepoint_len(ptstr, ptstr+1, &clen, enc);
 
@@ -8458,7 +8458,7 @@ rb_str_count(int argc, VALUE *argv, VALUE str)
             while (s < send) {
                 if (*(unsigned char*)s++ == c) n++;
             }
-            return SIZET2NUM(n);
+            return INT2NUM(n);
         }
     }
 
@@ -8474,12 +8474,13 @@ rb_str_count(int argc, VALUE *argv, VALUE str)
     if (!s || RSTRING_LEN(str) == 0) return INT2FIX(0);
     send = RSTRING_END(str);
     ascompat = rb_enc_asciicompat(enc);
+    i = 0;
     while (s < send) {
         unsigned int c;
 
         if (ascompat && (c = *(unsigned char*)s) < 0x80) {
             if (table[c]) {
-                n++;
+                i++;
             }
             s++;
         }
@@ -8487,13 +8488,13 @@ rb_str_count(int argc, VALUE *argv, VALUE str)
             int clen;
             c = rb_enc_codepoint_len(s, send, &clen, enc);
             if (tr_find(c, table, del, nodel)) {
-                n++;
+                i++;
             }
             s += clen;
         }
     }
 
-    return SIZET2NUM(n);
+    return INT2NUM(i);
 }
 
 static VALUE