diff --git a/lib/checkother.cpp b/lib/checkother.cpp
index bae7ea263..0f9378680 100644
--- a/lib/checkother.cpp
+++ b/lib/checkother.cpp
@@ -667,7 +667,7 @@ void CheckOther::checkRedundantAssignment()
                     if (!Token::simpleMatch(tok->tokAt(2), "0 ;") || (tok->variable() && tok->variable()->nameToken() != tok->tokAt(-2)))
                         varAssignments[tok->varId()] = tok;
                     memAssignments.erase(tok->varId());
-                } else if (tok->next()->type() == Token::eIncDecOp || (tok->previous()->type() == Token::eIncDecOp && !Token::Match(tok->next(), ".|[|("))) { // Variable incremented/decremented
+                } else if (tok->next()->type() == Token::eIncDecOp || (tok->previous()->type() == Token::eIncDecOp && tok->strAt(1) == ";")) { // Variable incremented/decremented; Prefix-Increment is only suspicious, if its return value is unused
                     varAssignments[tok->varId()] = tok;
                     memAssignments.erase(tok->varId());
                 } else if (!Token::simpleMatch(tok->tokAt(-2), "sizeof (")) { // Other usage of variable
diff --git a/test/testother.cpp b/test/testother.cpp
index c5d67c409..845b12fa2 100644
--- a/test/testother.cpp
+++ b/test/testother.cpp
@@ -5864,6 +5864,14 @@ private:
               "    i = 1;\n"
               "}", 0, false, false, false, false);
         ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:3]: (performance) Variable 'i' is reassigned a value before the old one has been used.\n", errout.str());
+
+        check("int foo() {\n" // #4420
+              "    int x;\n"
+              "    bar(++x);\n"
+              "    x = 5;\n"
+              "    return bar(x);\n"
+              "}");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void redundantMemWrite() {