diff --git a/lib/tokenize.cpp b/lib/tokenize.cpp
index 3ba3920d4..7a8408db0 100644
--- a/lib/tokenize.cpp
+++ b/lib/tokenize.cpp
@@ -6092,6 +6092,10 @@ bool Tokenizer::simplifyKnownVariables()
                     if (pointeralias && Token::Match(tok3, ("!!= " + value).c_str()))
                         break;
 
+                    // Stop if do is found
+                    if (tok3->str() == "do")
+                        break;
+
                     // Stop if something like 'while (--var)' is found
                     if (tok3->str() == "for" || tok3->str() == "while" || tok3->str() == "do")
                     {
diff --git a/test/testtokenize.cpp b/test/testtokenize.cpp
index 2edf9dd71..142214609 100644
--- a/test/testtokenize.cpp
+++ b/test/testtokenize.cpp
@@ -120,6 +120,7 @@ private:
         TEST_CASE(simplifyKnownVariables31);
         TEST_CASE(simplifyKnownVariables32);    // const
         TEST_CASE(simplifyKnownVariables33);    // struct variable
+        TEST_CASE(simplifyKnownVariables34);
         TEST_CASE(simplifyKnownVariablesBailOutAssign);
         TEST_CASE(simplifyKnownVariablesBailOutFor1);
         TEST_CASE(simplifyKnownVariablesBailOutFor2);
@@ -1852,6 +1853,21 @@ private:
         ASSERT_EQUALS(expected, tokenizeAndStringify(code, true));
     }
 
+    void simplifyKnownVariables34()
+    {
+        const char code[] = "void f() {\n"
+                            "    int x = 10;\n"
+                            "    do { cin >> x; } while (x > 5);\n"
+                            "    a[x] = 0;\n"
+                            "}\n";
+        const char expected[] = "void f ( ) {\n"
+                                "int x ; x = 10 ;\n"
+                                "do { cin >> x ; } while ( 5 < x ) ;\n"
+                                "a [ x ] = 0 ;\n"
+                                "}";
+        ASSERT_EQUALS(expected, tokenizeAndStringify(code, true));
+    }
+
     void simplifyKnownVariablesBailOutAssign()
     {
         const char code[] = "int foo() {\n"