diff --git a/cli/cmdlineparser.cpp b/cli/cmdlineparser.cpp
index 2b4bf8587..64012af97 100644
--- a/cli/cmdlineparser.cpp
+++ b/cli/cmdlineparser.cpp
@@ -181,6 +181,14 @@ bool CmdLineParser::parseFromArgs(int argc, const char* const argv[])
             else if (std::strcmp(argv[i], "--inconclusive") == 0)
                 mSettings->inconclusive = true;
 
+            // Experimental: Safe checking
+            else if (std::strcmp(argv[i], "--safe-classes") == 0)
+                mSettings->safeChecks.classes = true;
+
+            // Experimental: Safe checking
+            else if (std::strcmp(argv[i], "--safe-functions") == 0)
+                mSettings->safeChecks.externalFunctions = mSettings->safeChecks.internalFunctions = true;
+
             // Enforce language (--language=, -x)
             else if (std::strncmp(argv[i], "--language=", 11) == 0 || std::strcmp(argv[i], "-x") == 0) {
                 std::string str;
diff --git a/lib/check.cpp b/lib/check.cpp
index c173b3518..4ae15e2c7 100644
--- a/lib/check.cpp
+++ b/lib/check.cpp
@@ -66,3 +66,12 @@ std::list<Check *> &Check::instances()
     return _instances;
 #endif
 }
+
+std::string Check::getMessageId(const ValueFlow::Value &value, const char id[])
+{
+    if (value.condition != nullptr)
+        return id + std::string("Cond");
+    if (value.safe)
+        return std::string("safe") + (char)std::toupper(id[0]) + (id + 1);
+    return id;
+}
diff --git a/lib/check.h b/lib/check.h
index 82ad4c5e1..0c20ebf1b 100644
--- a/lib/check.h
+++ b/lib/check.h
@@ -118,6 +118,8 @@ public:
         return false;
     }
 
+    static std::string getMessageId(const ValueFlow::Value &value, const char id[]);
+
 protected:
     const Tokenizer * const mTokenizer;
     const Settings * const mSettings;
diff --git a/lib/checktype.cpp b/lib/checktype.cpp
index e18aeceba..9d09f7d79 100644
--- a/lib/checktype.cpp
+++ b/lib/checktype.cpp
@@ -200,9 +200,12 @@ void CheckType::integerOverflowError(const Token *tok, const ValueFlow::Value &v
     else
         msg = "Signed integer overflow for expression '" + expr + "'.";
 
+    if (value.safe)
+        msg = "Safe checks: " + msg;
+
     reportError(getErrorPath(tok, &value, "Integer overflow"),
                 value.errorSeverity() ? Severity::error : Severity::warning,
-                (value.condition == nullptr) ? "integerOverflow" : "integerOverflowCond",
+                getMessageId(value, "integerOverflow").c_str(),
                 msg,
                 CWE190,
                 value.isInconclusive());
diff --git a/lib/valueflow.cpp b/lib/valueflow.cpp
index 1d6a5fcef..2d2c5caca 100644
--- a/lib/valueflow.cpp
+++ b/lib/valueflow.cpp
@@ -374,6 +374,7 @@ static void combineValueProperties(const ValueFlow::Value &value1, const ValueFl
     result->varId = (value1.varId != 0U) ? value1.varId : value2.varId;
     result->varvalue = (result->varId == value1.varId) ? value1.varvalue : value2.varvalue;
     result->errorPath = (value1.errorPath.empty() ? value2 : value1).errorPath;
+    result->safe = value1.safe || value2.safe;
 }
 
 
@@ -5462,9 +5463,11 @@ static void valueFlowSafeFunctions(TokenList *tokenlist, SymbolDatabase *symbold
                 argValues.emplace_back(0);
                 argValues.back().valueType = ValueFlow::Value::ValueType::CONTAINER_SIZE;
                 argValues.back().errorPath.emplace_back(arg.nameToken(), "Assuming " + arg.name() + " is empty");
+                argValues.back().safe = true;
                 argValues.emplace_back(1000000);
                 argValues.back().valueType = ValueFlow::Value::ValueType::CONTAINER_SIZE;
                 argValues.back().errorPath.emplace_back(arg.nameToken(), "Assuming " + arg.name() + " size is 1000000");
+                argValues.back().safe = true;
                 for (const ValueFlow::Value &value : argValues)
                     valueFlowContainerForward(const_cast<Token*>(functionScope->bodyStart), arg.declarationId(), value, settings, tokenlist->isCPP());
                 continue;
@@ -5477,6 +5480,9 @@ static void valueFlowSafeFunctions(TokenList *tokenlist, SymbolDatabase *symbold
             if (!isLow && !isHigh && !all)
                 continue;
 
+            const bool safeLow = !isLow;
+            const bool safeHigh = !isHigh;
+
             if ((!isLow || !isHigh) && all) {
                 MathLib::bigint minValue, maxValue;
                 if (getMinMaxValues(arg.valueType(), *settings, &minValue, &maxValue)) {
@@ -5490,11 +5496,13 @@ static void valueFlowSafeFunctions(TokenList *tokenlist, SymbolDatabase *symbold
                     argValues.emplace_back(0);
                     argValues.back().valueType = ValueFlow::Value::ValueType::FLOAT;
                     argValues.back().floatValue = isLow ? low : -1E25f;
-                    argValues.back().errorPath.emplace_back(arg.nameToken(), "Assuming argument has value " + MathLib::toString(argValues.back().floatValue));
+                    argValues.back().errorPath.emplace_back(arg.nameToken(), "Safe checks: Assuming argument has value " + MathLib::toString(argValues.back().floatValue));
+                    argValues.back().safe = true;
                     argValues.emplace_back(0);
                     argValues.back().valueType = ValueFlow::Value::ValueType::FLOAT;
                     argValues.back().floatValue = isHigh ? high : 1E25f;
-                    argValues.back().errorPath.emplace_back(arg.nameToken(), "Assuming argument has value " + MathLib::toString(argValues.back().floatValue));
+                    argValues.back().errorPath.emplace_back(arg.nameToken(), "Safe checks: Assuming argument has value " + MathLib::toString(argValues.back().floatValue));
+                    argValues.back().safe = true;
                     valueFlowForward(const_cast<Token *>(functionScope->bodyStart->next()),
                                      functionScope->bodyEnd,
                                      &arg,
@@ -5512,11 +5520,13 @@ static void valueFlowSafeFunctions(TokenList *tokenlist, SymbolDatabase *symbold
             std::list<ValueFlow::Value> argValues;
             if (isLow) {
                 argValues.emplace_back(low);
-                argValues.back().errorPath.emplace_back(arg.nameToken(), "Assuming argument has value " + MathLib::toString(low));
+                argValues.back().errorPath.emplace_back(arg.nameToken(), std::string(safeLow ? "Safe checks: " : "") + "Assuming argument has value " + MathLib::toString(low));
+                argValues.back().safe = safeLow;
             }
             if (isHigh) {
                 argValues.emplace_back(high);
-                argValues.back().errorPath.emplace_back(arg.nameToken(), "Assuming argument has value " + MathLib::toString(high));
+                argValues.back().errorPath.emplace_back(arg.nameToken(), std::string(safeHigh ? "Safe checks: " : "") + "Assuming argument has value " + MathLib::toString(high));
+                argValues.back().safe = safeHigh;
             }
 
             if (!argValues.empty())
@@ -5574,6 +5584,7 @@ ValueFlow::Value::Value(const Token *c, long long val)
       varvalue(val),
       condition(c),
       varId(0U),
+      safe(false),
       conditional(false),
       defaultArg(false),
       lifetimeKind(LifetimeKind::Object),
diff --git a/lib/valueflow.h b/lib/valueflow.h
index 54e46b65d..62a7c7c37 100644
--- a/lib/valueflow.h
+++ b/lib/valueflow.h
@@ -50,6 +50,7 @@ namespace ValueFlow {
               varvalue(val),
               condition(nullptr),
               varId(0U),
+              safe(false),
               conditional(false),
               defaultArg(false),
               lifetimeKind(LifetimeKind::Object),
@@ -161,6 +162,9 @@ namespace ValueFlow {
         /** For calculated values - varId that calculated value depends on */
         nonneg int varId;
 
+        /** value relies on safe checking */
+        bool safe;
+
         /** Conditional value */
         bool conditional;