diff --git a/CMakeLists.txt b/CMakeLists.txt
index 37c83594..732ff2d1 100755
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -275,13 +275,17 @@ endif()
 # Linear
 # ------
 
-# Accelerate solver (Include before Eigen)
+
 if(POLYSOLVE_WITH_ACCELERATE)
-    set(BLA_VENDOR Apple)
-    find_package(BLAS REQUIRED)
-    find_package(LAPACK REQUIRED)
-    target_link_libraries(polysolve_linear PRIVATE BLAS::BLAS LAPACK::LAPACK)
-    target_compile_definitions(polysolve_linear PUBLIC POLYSOLVE_WITH_ACCELERATE)
+    if(POLYSOLVE_LARGE_INDEX)
+        message(STATUS "POLYSOLVE_LARGE_INDEX is ON: disabling Apple Accelerate (it only supports 32-bit sparse indices).")
+    else()
+        set(BLA_VENDOR Apple)
+        find_package(BLAS REQUIRED)
+        find_package(LAPACK REQUIRED)
+        target_link_libraries(polysolve_linear PRIVATE BLAS::BLAS LAPACK::LAPACK)
+        target_compile_definitions(polysolve_linear PUBLIC POLYSOLVE_WITH_ACCELERATE)
+    endif()
 endif()
 
 include(eigen)
diff --git a/src/polysolve/linear/Solver.cpp b/src/polysolve/linear/Solver.cpp
index 4334ac6f..ccdb40f6 100644
--- a/src/polysolve/linear/Solver.cpp
+++ b/src/polysolve/linear/Solver.cpp
@@ -45,8 +45,12 @@ namespace polysolve::linear
 #include <Eigen/SuperLUSupport>
 #endif
 #ifdef POLYSOLVE_WITH_MKL
+#ifndef POLYSOLVE_LARGE_INDEX
+// Eigen's PardisoSupport only specializes for int/long long indices, not the
+// std::ptrdiff_t (long) StiffnessMatrix used with POLYSOLVE_LARGE_INDEX.
 #include <Eigen/PardisoSupport>
 #endif
+#endif
 #ifdef POLYSOLVE_WITH_PARDISO
 #include "Pardiso.hpp"
 #endif
@@ -368,6 +372,7 @@ namespace polysolve::linear
             RETURN_DIRECT_SOLVER_PTR(SPQR, "Eigen::SPQR");
 #endif
 #ifdef POLYSOLVE_WITH_MKL
+#ifndef POLYSOLVE_LARGE_INDEX
         }
         else if (solver == "Eigen::PardisoLLT")
         {
@@ -381,6 +386,7 @@ namespace polysolve::linear
         {
             RETURN_DIRECT_SOLVER_PTR(PardisoLU, "Eigen::PardisoLU");
 #endif
+#endif
 #ifdef POLYSOLVE_WITH_PARDISO
         }
         else if (solver == "Pardiso")
@@ -524,10 +530,12 @@ namespace polysolve::linear
             "Eigen::SPQR",
 #endif
 #ifdef POLYSOLVE_WITH_MKL
+#ifndef POLYSOLVE_LARGE_INDEX
             "Eigen::PardisoLLT",
             "Eigen::PardisoLDLT",
             "Eigen::PardisoLU",
 #endif
+#endif
 #ifdef POLYSOLVE_WITH_PARDISO
             "Pardiso",
 #endif