diff --git a/lib/tokenize.cpp b/lib/tokenize.cpp
index 1f1d1ca9e..221adf499 100644
--- a/lib/tokenize.cpp
+++ b/lib/tokenize.cpp
@@ -4591,6 +4591,18 @@ void Tokenizer::simplifyCasts()
             tok = tok->linkAt(2);
             continue;
         }
+        // #4164 : ((unsigned char)1) => (1)
+        if (Token::Match(tok->next(), "( unsigned| %type% ) %num%") && tok->next()->link()->previous()->isStandardType()) {
+            const MathLib::bigint value = MathLib::toLongNumber(tok->next()->link()->next()->str());
+            unsigned int bits = 8 * _typeSize[tok->next()->link()->previous()->str()];
+            if (!tok->tokAt(2)->isUnsigned())
+                bits--;
+            if (bits < 31 && value >= 0 && value < (1 << bits)) {
+                Token::eraseTokens(tok, tok->next()->link()->next());
+            }
+            continue;
+        }
+
         while ((Token::Match(tok->next(), "( %type% *| *| *| ) *|&| %var%") && (tok->str() != ")" || tok->tokAt(2)->isStandardType())) ||
                Token::Match(tok->next(), "( %type% %type% *| *| *| ) *|&| %var%") ||
                (!tok->isName() && (Token::Match(tok->next(), "( %type% * *| *| ) (") ||
diff --git a/test/testsimplifytokens.cpp b/test/testsimplifytokens.cpp
index 7b8483e2e..4b7ea0285 100644
--- a/test/testsimplifytokens.cpp
+++ b/test/testsimplifytokens.cpp
@@ -509,6 +509,10 @@ private:
 
         // no simplification as the cast may be important here. see #2897 for example
         ASSERT_EQUALS("; * ( ( char * ) p + 1 ) = 0 ;", tok("; *((char *)p + 1) = 0;"));
+
+        ASSERT_EQUALS("if ( true )", tok("if ((unsigned char)1)")); // #4164
+        ASSERT_EQUALS("f ( 200 )", tok("f((unsigned char)200)"));
+        ASSERT_EQUALS("f ( ( char ) 1234 )", tok("f((char)1234)")); // dont simplify downcast
     }