diff --git a/cmake/compiler_utils.cmake b/cmake/compiler_utils.cmake
index 4fca09284..e59a32e91 100644
--- a/cmake/compiler_utils.cmake
+++ b/cmake/compiler_utils.cmake
@@ -8,7 +8,7 @@ endfunction()
 # Prepares warnings setup for current target
 function(compiler_get_warnings_setup VARNAME)
     if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
-        set(WARNINGS_SETUP "-Wall -Wextra -pedantic -Wconversion -Wno-long-long")
+        set(WARNINGS_SETUP "-Wall -Wextra -pedantic -Wconversion -Wsign-conversion -Wno-long-long")
     elseif ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
         set(WARNINGS_SETUP_LIST "-Weverything"
                 "-Wno-system-headers"
diff --git a/compiler/extensions/cpp/runtime/src/zserio/DeltaContext.h b/compiler/extensions/cpp/runtime/src/zserio/DeltaContext.h
index bf587daf6..03cb1f037 100644
--- a/compiler/extensions/cpp/runtime/src/zserio/DeltaContext.h
+++ b/compiler/extensions/cpp/runtime/src/zserio/DeltaContext.h
@@ -139,7 +139,7 @@ class DeltaContext
         }
         else
         {
-            return m_maxBitNumber + (m_maxBitNumber > 0 ? 1 : 0);
+            return static_cast<size_t>(m_maxBitNumber + (m_maxBitNumber > 0 ? 1 : 0));
         }
     }
 
@@ -273,7 +273,7 @@ class DeltaContext
     {
         if (isFlagSet(IS_PACKED_FLAG))
         {
-            const size_t deltaBitSize = m_maxBitNumber + (m_maxBitNumber > 0 ? 1 : 0);
+            const size_t deltaBitSize = static_cast<size_t>(m_maxBitNumber + (m_maxBitNumber > 0 ? 1 : 0));
             const size_t packedBitSizeWithDescriptor = 1 + MAX_BIT_NUMBER_BITS + // descriptor
                     m_firstElementBitSize + (m_numElements - 1) * deltaBitSize;
             const size_t unpackedBitSizeWithDescriptor = 1 + m_unpackedBitSize;