diff --git a/lib/checkcondition.cpp b/lib/checkcondition.cpp
index 64c025a9f..67cbbbc1b 100644
--- a/lib/checkcondition.cpp
+++ b/lib/checkcondition.cpp
@@ -143,6 +143,9 @@ bool CheckCondition::assignIfParseScope(const Token * const assignTok,
                     else if (op == "!=" && (num & num2) != ((bitop=='&') ? num2 : num))
                         assignIfError(assignTok, tok2, condition, true);
                 }
+                if (Token::Match(tok2, "%varid% %op%", varid) && tok2->next()->isAssignmentOp()) {
+                    return true;
+                }
             }
 
             bool ret1 = assignIfParseScope(assignTok, end->tokAt(2), varid, islocal, bitop, num);
diff --git a/test/testcondition.cpp b/test/testcondition.cpp
index 3e5b261bb..3a6385963 100644
--- a/test/testcondition.cpp
+++ b/test/testcondition.cpp
@@ -255,6 +255,22 @@ private:
               "  }\n"
               "}\n");
         ASSERT_EQUALS("", errout.str());
+
+        check("void f(int a) {\n" // #6662
+              "  int x = a & 1;\n"
+              "  while (x <= 4) {\n"
+              "    if (x != 5) {}\n"
+              "  }\n"
+              "}\n");
+        ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:4]: (style) Mismatching assignment and comparison, comparison 'x!=5' is always true.\n", errout.str());
+
+        check("void f(int a) {\n" // #6662
+              "  int x = a & 1;\n"
+              "  while ((x += 4) < 10) {\n"
+              "    if (x != 5) {}\n"
+              "  }\n"
+              "}\n");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void mismatchingBitAnd() {