diff --git a/lib/mathlib.cpp b/lib/mathlib.cpp
index 68a3cae82f6..c23182a5a63 100644
--- a/lib/mathlib.cpp
+++ b/lib/mathlib.cpp
@@ -344,8 +344,13 @@ MathLib::biguint MathLib::toBigUNumber(const std::string & str, const Token * co
         return static_cast<biguint>(static_cast<bigint>(doubleval));
     }
 
-    if (isCharLiteral(str))
-        return simplecpp::characterLiteralToLL(str);
+    if (isCharLiteral(str)) {
+        try {
+            return simplecpp::characterLiteralToLL(str);
+        } catch (const std::runtime_error& e) {
+            throw InternalError(tok, "Internal Error. MathLib::toBigUNumber: characterLiteralToLL(" + str + ") => " + e.what());
+        }
+    }
 
     try {
         std::size_t idx = 0;
@@ -429,8 +434,13 @@ MathLib::bigint MathLib::toBigNumber(const std::string & str, const Token * cons
         return static_cast<bigint>(doubleval);
     }
 
-    if (isCharLiteral(str))
-        return simplecpp::characterLiteralToLL(str);
+    if (isCharLiteral(str)) {
+        try {
+            return simplecpp::characterLiteralToLL(str);
+        } catch (const std::runtime_error& e) {
+            throw InternalError(tok, "Internal Error. MathLib::toBigNumber: characterLiteralToLL(" + str + ") => " + e.what());
+        }
+    }
 
     try {
         std::size_t idx = 0;
@@ -505,7 +515,7 @@ double MathLib::toDoubleNumber(const std::string &str, const Token * const tok)
     if (isCharLiteral(str)) {
         try {
             return simplecpp::characterLiteralToLL(str);
-        } catch (const std::exception& e) {
+        } catch (const std::runtime_error& e) {
             throw InternalError(tok, "Internal Error. MathLib::toDoubleNumber: characterLiteralToLL(" + str + ") => " + e.what());
         }
     }
diff --git a/lib/tokenize.cpp b/lib/tokenize.cpp
index aaed296dc4c..0763207fe92 100644
--- a/lib/tokenize.cpp
+++ b/lib/tokenize.cpp
@@ -3470,7 +3470,7 @@ bool Tokenizer::simplifyTokens1(const std::string &configuration, int fileIndex)
             if (tok->tokType() == Token::eChar && tok->values().empty()) {
                 try {
                     simplecpp::characterLiteralToLL(tok->str());
-                } catch (const std::exception &e) {
+                } catch (const std::runtime_error &e) {
                     unhandledCharLiteral(tok, e.what());
                 }
             }
diff --git a/test/testmathlib.cpp b/test/testmathlib.cpp
index 6a0ba4c0871..a2f9526162c 100644
--- a/test/testmathlib.cpp
+++ b/test/testmathlib.cpp
@@ -416,6 +416,8 @@ class TestMathLib : public TestFixture {
             TokenList::deleteTokens(tok);
         }
 
+        ASSERT_THROW_INTERNAL_EQUALS(MathLib::toBigNumber("''"), INTERNAL, "Internal Error. MathLib::toBigNumber: characterLiteralToLL('') => empty character literal");
+
         // TODO: test binary
         // TODO: test floating point
 
@@ -588,6 +590,8 @@ class TestMathLib : public TestFixture {
             TokenList::deleteTokens(tok);
         }
 
+        ASSERT_THROW_INTERNAL_EQUALS(MathLib::toBigUNumber("''"), INTERNAL, "Internal Error. MathLib::toBigUNumber: characterLiteralToLL('') => empty character literal");
+
         // TODO: test binary
         // TODO: test floating point
 
@@ -736,6 +740,8 @@ class TestMathLib : public TestFixture {
         ASSERT_EQUALS("0.0",  MathLib::toString(MathLib::toDoubleNumber("-0")));
         ASSERT_EQUALS("0.0",  MathLib::toString(MathLib::toDoubleNumber("-0.")));
         ASSERT_EQUALS("0.0",  MathLib::toString(MathLib::toDoubleNumber("-0.0")));
+
+        ASSERT_THROW_INTERNAL_EQUALS(MathLib::toDoubleNumber("''"), INTERNAL, "Internal Error. MathLib::toDoubleNumber: characterLiteralToLL('') => empty character literal");
     }
 
     void isint() const {