diff --git a/lib/checkfunctions.cpp b/lib/checkfunctions.cpp
index 6135a6625..3b345d025 100644
--- a/lib/checkfunctions.cpp
+++ b/lib/checkfunctions.cpp
@@ -381,7 +381,9 @@ void CheckFunctions::memsetInvalid2ndParam()
 
             if (printWarning && secondParamTok->isNumber()) { // Check if the second parameter is a literal and is out of range
                 const long long int value = MathLib::toLongNumber(secondParamTok->str());
-                if (value < -128 || value > 255) // FIXME: Use platform char_bits
+                const long long sCharMin = _settings->signedCharMin();
+                const long long uCharMax = _settings->unsignedCharMax();
+                if (value < sCharMin || value > uCharMax)
                     memsetValueOutOfRangeError(secondParamTok, secondParamTok->str());
             }
         }
diff --git a/lib/platform.h b/lib/platform.h
index 2824d1b7e..3e316de8a 100644
--- a/lib/platform.h
+++ b/lib/platform.h
@@ -131,6 +131,18 @@ namespace cppcheck {
                 return "unknown";
             }
         }
+
+        long long unsignedCharMax() const {
+            return max_value(char_bit + 1); 
+        }
+
+        long long signedCharMax() const {
+            return max_value(char_bit);
+        }
+
+        long long signedCharMin() const {
+            return min_value(char_bit);
+        }
     };
 
 }
diff --git a/lib/valueflow.cpp b/lib/valueflow.cpp
index 3cb9c058d..23b02df42 100644
--- a/lib/valueflow.cpp
+++ b/lib/valueflow.cpp
@@ -303,8 +303,8 @@ static void setTokenValue(Token* tok, const ValueFlow::Value &value, const Setti
         else if (valueType.type == ValueType::Type::LONGLONG)
             setTokenValue(parent, castValue(value, valueType.sign, settings->long_long_bit), settings);
         else if (value.isIntValue()) {
-            const int charMax = (1 << (settings->char_bit - 1)) - 1;
-            const int charMin = -charMax - 1;
+            const long long charMax = settings->signedCharMax();
+            const long long charMin = settings->signedCharMin();
             if (charMin <= value.intvalue && value.intvalue <= charMax) {
                 // unknown type, but value is small so there should be no truncation etc
                 setTokenValue(parent,value,settings);