diff --git a/cmake/compileroptions.cmake b/cmake/compileroptions.cmake
index f6649328d..8f6e957ff 100644
--- a/cmake/compileroptions.cmake
+++ b/cmake/compileroptions.cmake
@@ -32,6 +32,10 @@ if (USE_ANALYZE)
     set (CMAKE_CXX_FLAGS_RELEASE        "-O2")
 endif()
 
+set(CMAKE_CXX_FLAGS_ASAN "-g -fsanitize=address,undefined -fno-sanitize-recover=all"
+    CACHE STRING "Compiler flags in asan build"
+    FORCE)
+
 if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
     execute_process(COMMAND ${CMAKE_CXX_COMPILER} -dumpversion OUTPUT_VARIABLE GCC_VERSION)
     if (NOT (GCC_VERSION VERSION_GREATER 4.6 OR GCC_VERSION VERSION_EQUAL 4.6))
diff --git a/lib/mathlib.cpp b/lib/mathlib.cpp
index 21862000e..28265421a 100644
--- a/lib/mathlib.cpp
+++ b/lib/mathlib.cpp
@@ -270,6 +270,9 @@ MathLib::value MathLib::value::shiftLeft(const MathLib::value &v) const
     if (!isInt() || !v.isInt())
         throw InternalError(nullptr, "Shift operand is not integer");
     MathLib::value ret(*this);
+    if (v.intValue >= MathLib::bigint_bits) {
+        return ret;
+    }
     ret.intValue <<= v.intValue;
     return ret;
 }
@@ -279,6 +282,9 @@ MathLib::value MathLib::value::shiftRight(const MathLib::value &v) const
     if (!isInt() || !v.isInt())
         throw InternalError(nullptr, "Shift operand is not integer");
     MathLib::value ret(*this);
+    if (v.intValue >= MathLib::bigint_bits) {
+        return ret;
+    }
     ret.intValue >>= v.intValue;
     return ret;
 }
diff --git a/lib/valueflow.cpp b/lib/valueflow.cpp
index 41004198b..d61a2bfc6 100644
--- a/lib/valueflow.cpp
+++ b/lib/valueflow.cpp
@@ -2514,7 +2514,7 @@ static void execute(const Token *expr,
         else if (expr->str() == "%")
             *result = result1 % result2;
         else if (expr->str() == "<<")  {
-            if (result2 < 0 || result1 < 0)  { // don't perform UB
+            if (result2 < 0 || result1 < 0 || result2 >= MathLib::bigint_bits)  { // don't perform UB
                 *error= true;
             } else {
                 *result = result1 << result2;