diff --git a/.github/workflows/cmake-multi-platform.yml b/.github/workflows/cmake-multi-platform.yml
index d56b3ac..d2605c9 100644
--- a/.github/workflows/cmake-multi-platform.yml
+++ b/.github/workflows/cmake-multi-platform.yml
@@ -50,12 +50,22 @@ jobs:
       run: echo "dir=${{ github.workspace }}/build" >> "$GITHUB_OUTPUT"
 
     - name: Configure CMake
-      run: >
-        cmake -B ${{ steps.vars.outputs.dir }}
-        -DCMAKE_CXX_COMPILER=${{ matrix.cpp_compiler }}
-        -DCMAKE_C_COMPILER=${{ matrix.c_compiler }}
-        -DCMAKE_BUILD_TYPE=${{ matrix.build_type }}
-        -S ${{ github.workspace }}
+      shell: bash
+      run: |
+        CXX_FLAGS=""
+        LINK_FLAGS=""
+        if [[ "${{ matrix.os }}" == "ubuntu-latest" && "${{ matrix.build_type }}" == "Debug" ]]; then
+          CXX_FLAGS="-fsanitize=address,undefined -fno-omit-frame-pointer -g"
+          LINK_FLAGS="-fsanitize=address,undefined"
+        fi
+
+        cmake -B "${{ steps.vars.outputs.dir }}" \
+              -DCMAKE_C_COMPILER=${{ matrix.c_compiler }} \
+              -DCMAKE_CXX_COMPILER=${{ matrix.cpp_compiler }} \
+              -DCMAKE_BUILD_TYPE=${{ matrix.build_type }} \
+              -DCMAKE_CXX_FLAGS_DEBUG="$CXX_FLAGS" \
+              -DCMAKE_EXE_LINKER_FLAGS="$LINK_FLAGS" \
+              -S "${{ github.workspace }}"
 
     - name: Build
       run: cmake --build ${{ steps.vars.outputs.dir }} --config ${{ matrix.build_type }}
@@ -68,4 +78,4 @@ jobs:
           ctest --build-config ${{ matrix.build_type }} --verbose
         else
           ctest --verbose
-        fi
\ No newline at end of file
+        fi
diff --git a/position.h b/position.h
index 9f6f01f..01684f1 100644
--- a/position.h
+++ b/position.h
@@ -149,7 +149,7 @@ template <typename T, std::size_t MaxSize> class HeapAllocatedValueList {
 };
 
 enum class MoveGenType : uint8_t { ALL, PAWN, KNIGHT, BISHOP, ROOK, QUEEN, KING, CAPTURE };
-template <typename PieceC = EnginePiece, typename = std::enable_if_t<std::is_same_v<PieceC, EnginePiece> || std::is_same_v<PieceC, PolyglotPiece> || std::is_same_v<PieceC, ContiguousMappingPiece>>> class _Position {
+template <typename PieceC = EnginePiece, typename = std::enable_if_t<is_piece_enum<PieceC>::value>> class _Position {
   private:
     HistoryEntry<PieceC> current_state;
 
@@ -524,6 +524,8 @@ template <typename PieceC = EnginePiece, typename = std::enable_if_t<std::is_sam
         }
         return b != 0;
     }
+    // Material-only key (note: Zobrist=Zpieces^Zep^Zcastling^Zturn, we just XORs the remaining, it's trivial)
+    __FORCEINLINE Key material_key() const { return hash() ^ (zobrist::RandomTurn * ~sideToMove()) ^ (zobrist::RandomCastle[castlingRights()]) ^ (zobrist::RandomEP[ep_square() == SQ_NONE ? file_of(ep_square()) : FILE_NB]); }
     template <bool Strict = false> bool is_valid() const;
 
   private: