diff --git a/recipes/vcf-validator/build.sh b/recipes/vcf-validator/build.sh
index f4ffec24e861c3..341afcd3c5dd0d 100644
--- a/recipes/vcf-validator/build.sh
+++ b/recipes/vcf-validator/build.sh
@@ -5,9 +5,17 @@ set -x
 # Set c++ to version 11
 export CXXFLAGS="-std=c++11 ${CXXFLAGS}"
 
+case $(uname -m) in 
+  aarch64 | arm64)
+    export CXXFLAGS="${CXXFLAGS} -funsigned-char" # .../vcf/compression.cpp:101:9: error: narrowing conversion of '-117' from 'int' to 'char'
+    ;;
+  *)
+    ;;
+esac
+
 mkdir build || { echo "Failed to create build directory" >&2; exit 1; }
 cd build || { echo "Failed to go into build directory" >&2; exit 1; }
-cmake -G "Unix Makefiles" ..
+cmake -G "Unix Makefiles" -DCMAKE_CXX_FLAGS="${CXXFLAGS}" ..
 make -j"${CPU_COUNT}" || { echo "Build failed" >&2; exit 1; }
 cd .. || { echo "Failed to return to parent directory" >&2; exit 1; }
 if ! ./build/bin/test_validation_suite; then