diff --git a/lib/tokenize.cpp b/lib/tokenize.cpp
index a7e7b7473..7b2dcbe8b 100644
--- a/lib/tokenize.cpp
+++ b/lib/tokenize.cpp
@@ -3503,6 +3503,16 @@ bool Tokenizer::simplifyTokenList()
         modified |= simplifyConditions();
         modified |= simplifyFunctionReturn();
         modified |= simplifyKnownVariables();
+
+        // replace strlen(str)
+        for (Token *tok = list.front(); tok; tok = tok->next()) {
+            if (Token::Match(tok, "strlen ( %str% )")) {
+                tok->str(MathLib::longToString(Token::getStrLength(tok->tokAt(2))));
+                tok->deleteNext(3);
+                modified = true;
+            }
+        }
+
         modified |= removeRedundantConditions();
         modified |= simplifyRedundantParentheses();
         modified |= simplifyConstTernaryOp();
@@ -3511,16 +3521,6 @@ bool Tokenizer::simplifyTokenList()
 
     simplifyConditionOperator();
 
-    // replace strlen(str)
-    for (Token *tok = list.front(); tok; tok = tok->next()) {
-        if (Token::Match(tok, "strlen ( %str% )")) {
-            std::ostringstream ostr;
-            ostr << Token::getStrLength(tok->tokAt(2));
-            tok->str(ostr.str());
-            tok->deleteNext(3);
-        }
-    }
-
     // simplify redundant for
     removeRedundantFor();
 
diff --git a/test/testsimplifytokens.cpp b/test/testsimplifytokens.cpp
index d4239e88e..189a88113 100644
--- a/test/testsimplifytokens.cpp
+++ b/test/testsimplifytokens.cpp
@@ -91,6 +91,7 @@ private:
         TEST_CASE(casting);
 
         TEST_CASE(strlen1);
+        TEST_CASE(strlen2);
 
         TEST_CASE(template1);
         TEST_CASE(template2);
@@ -1651,7 +1652,11 @@ private:
 
     }
 
-
+    void strlen2() {
+        // #4530 - make sure calculation with strlen is simplified
+        ASSERT_EQUALS("i = -4 ;",
+                      tok("i = (strlen(\"abcd\") - 8);"));
+    }