diff --git a/include/utils/errors.h b/include/utils/errors.h
index 6e2511638..fc40138dc 100644
--- a/include/utils/errors.h
+++ b/include/utils/errors.h
@@ -26,6 +26,11 @@
 #define ERRORS_H
 
 #include <sstream>
+#include <limits>
+#include <cstdint>
+#include <charconv>
+#include <string_view>
+#include <system_error>
 
 enum class ReturnValue {
     SuccessCode = 0,
@@ -66,4 +71,34 @@ struct base_error : public std::exception {
     }
 };
 
+inline uint32_t toBoundedTokenCount(uint64_t count) {
+    if (count > std::numeric_limits<uint32_t>::max()) {
+        throw base_error("Number of tokens exceeded ", std::numeric_limits<uint32_t>::max());
+    }
+    return static_cast<uint32_t>(count);
+}
+
+inline int32_t parse_bounded_int32(std::string_view text) {
+    if (text.empty()) {
+        throw base_error("Expected an integer constant, got \"\"");
+    }
+
+    int32_t value = 0;
+    const char* const first = text.data();
+    const char* const last = first + text.size();
+    const std::from_chars_result result = std::from_chars(first, last, value);
+    if (result.ec == std::errc::invalid_argument || result.ptr == first || result.ptr != last) {
+        throw base_error("Expected an integer constant, got \"", text, "\"");
+    }
+    if (result.ec == std::errc::result_out_of_range) {
+        if (text.front() == '-') {
+            throw base_error("Integer constant ", text, " is less than ",
+                             std::numeric_limits<int32_t>::min());
+        }
+        throw base_error("Integer constant ", text, " exceeded ",
+                         std::numeric_limits<int32_t>::max());
+    }
+    return value;
+}
+
 #endif /* ERRORS_H */
diff --git a/src/PetriEngine/Colored/Multiset.cpp b/src/PetriEngine/Colored/Multiset.cpp
index 23dbbc19c..060becf1d 100644
--- a/src/PetriEngine/Colored/Multiset.cpp
+++ b/src/PetriEngine/Colored/Multiset.cpp
@@ -30,7 +30,7 @@ namespace PetriEngine {
                 : _set(), _type(nullptr)
         {
             for (auto& c : colors) {
-                (*this)[c.first] += c.second;
+                (*this)[c.first] = toBoundedTokenCount(static_cast<uint64_t>((*this)[c.first]) + c.second);
             }
         }
 
@@ -65,7 +65,7 @@ namespace PetriEngine {
                 const Color* color = &(*ColorType::dotInstance()->begin());
                 if (_type != nullptr)
                     color = &((*_type)[c.first]);
-                (*this)[color] += c.second;
+                (*this)[color] = toBoundedTokenCount(static_cast<uint64_t>((*this)[color]) + c.second);
             }
         }
 
@@ -86,7 +86,7 @@ namespace PetriEngine {
 
         void Multiset::operator *=(uint32_t scalar) {
             for (auto& c : _set) {
-                c.second *= scalar;
+                c.second = toBoundedTokenCount(static_cast<uint64_t>(c.second) * scalar);
             }
         }
 
diff --git a/src/PetriEngine/PQL/PQLQueryParser.y b/src/PetriEngine/PQL/PQLQueryParser.y
index 1cb0b17fa..20a026180 100644
--- a/src/PetriEngine/PQL/PQLQueryParser.y
+++ b/src/PetriEngine/PQL/PQLQueryParser.y
@@ -140,7 +140,10 @@ term	: term MULTIPLY factor	{ $$ = new MultiplyExpr(std::vector<Expr_ptr>({Expr_
 		;
 
 factor	: LPAREN expr RPAREN	{ $$ = $2; }
-		| INT			{ $$ = new LiteralExpr(atol($1->c_str())); delete $1; }
+		| INT			{
+		                    std::unique_ptr<std::string> token($1);
+		                    $$ = new LiteralExpr(parse_bounded_int32(*token));
+		                }
     | named         { $$ = $1; }
 		;
 
diff --git a/src/PetriParse/PNMLParser.cpp b/src/PetriParse/PNMLParser.cpp
index 4e8a6749a..482e7ad07 100644
--- a/src/PetriParse/PNMLParser.cpp
+++ b/src/PetriParse/PNMLParser.cpp
@@ -1005,7 +1005,7 @@ void PNMLParser::parseValue(rapidxml::xml_node<>* element, std::string& text) {
 uint32_t PNMLParser::parseNumberConstant(rapidxml::xml_node<>* element) {
     if (strcmp(element->name(), "numberconstant") == 0) {
         auto value = element->first_attribute("value")->value();
-        return (uint32_t)atoll(value);
+        return toBoundedTokenCount(static_cast<uint64_t>(atoll(value)));
     } else if (strcmp(element->name(), "subterm") == 0) {
         return parseNumberConstant(element->first_node());
     }
diff --git a/src/PetriParse/QueryXMLParser.cpp b/src/PetriParse/QueryXMLParser.cpp
index 813d3e3b8..9bdca72c2 100644
--- a/src/PetriParse/QueryXMLParser.cpp
+++ b/src/PetriParse/QueryXMLParser.cpp
@@ -466,13 +466,7 @@ Condition_ptr QueryXMLParser::parseBooleanFormula(rapidxml::xml_node<>*  element
 Expr_ptr QueryXMLParser::parseIntegerExpression(rapidxml::xml_node<>*  element) {
     std::string elementName = element->name();
     if (elementName == "integer-constant") {
-        int i;
-        if (sscanf(element->value(), "%d", &i) == EOF)
-        {
-            assert(false);
-            return nullptr;
-        }
-        return std::make_shared<LiteralExpr>(i);
+        return std::make_shared<LiteralExpr>(parse_bounded_int32(element->value()));
     } else if (elementName == "tokens-count") {
         auto children = element->first_node();
         std::vector<Expr_ptr> ids;