diff --git a/lib/token.cpp b/lib/token.cpp
index 2ec8b3fbe..0257ba688 100644
--- a/lib/token.cpp
+++ b/lib/token.cpp
@@ -1191,7 +1191,8 @@ std::string Token::expressionString() const
 {
     const Token * const top = this;
     const Token *start = top;
-    while (start->astOperand1() && (start->astOperand2() || Token::simpleMatch(start, "( )")))
+    while (start->astOperand1() &&
+           (start->astOperand2() || !start->isUnaryPreOp() || Token::simpleMatch(start, "( )")))
         start = start->astOperand1();
     const Token *end = top;
     while (end->astOperand1() && (end->astOperand2() || end->isUnaryPreOp())) {
@@ -1208,7 +1209,6 @@ std::string Token::expressionString() const
             ret += " ";
     }
     return ret + end->str();
-
 }
 
 static void astStringXml(const Token *tok, std::size_t indent, std::ostream &out)
diff --git a/test/testcondition.cpp b/test/testcondition.cpp
index 7fc45eab5..135f375da 100644
--- a/test/testcondition.cpp
+++ b/test/testcondition.cpp
@@ -1521,6 +1521,13 @@ private:
               "}");
         ASSERT_EQUALS("[test.cpp:4]: (style) Condition !x is always true\n", errout.str());
 
+        check("void f() {\n" // #6898 (Token::expressionString)
+              "  int x = 0;\n"
+              "  A(x++ == 1);\n"
+              "  A(x++ == 2);\n"
+              "}");
+        ASSERT_EQUALS("[test.cpp:4]: (style) Condition x++==2 is always false\n", errout.str());
+
         // Avoid FP when condition comes from macro
         check("void f() {\n"
               "  int x = 0;\n"