diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7014b4f..611d730 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -52,7 +52,7 @@ macro(warnings_high)
 endmacro()
 
 macro(oe_simulate target)
-  target_compile_definitions(${target} PRIVATE IS_REALLY_ADDRESS_SPACE_CONSTRAINED)
+  target_compile_definitions(${target} PRIVATE SNMALLOC_USE_SMALL_CHUNKS)
 endmacro()
 
 macro(clangformat_targets)
@@ -241,17 +241,21 @@ if(NOT DEFINED SNMALLOC_ONLY_HEADER_LIBRARY)
   if (SNMALLOC_STATIC_LIBRARY)
     add_shim(snmallocshim-static STATIC src/override/malloc.cc)
     add_shim(snmallocshim-1mib-static STATIC src/override/malloc.cc)
-    target_compile_definitions(snmallocshim-1mib-static PRIVATE IS_ADDRESS_SPACE_CONSTRAINED
+    add_shim(snmallocshim-16mib-static STATIC src/override/malloc.cc)
+    target_compile_definitions(snmallocshim-16mib-static PRIVATE SNMALLOC_USE_LARGE_CHUNKS
             SNMALLOC_STATIC_LIBRARY_PREFIX=${SNMALLOC_STATIC_LIBRARY_PREFIX})
     target_compile_definitions(snmallocshim-static PRIVATE
             SNMALLOC_STATIC_LIBRARY_PREFIX=${SNMALLOC_STATIC_LIBRARY_PREFIX})
+    target_compile_definitions(snmallocshim-1mib-static PRIVATE
+            SNMALLOC_STATIC_LIBRARY_PREFIX=${SNMALLOC_STATIC_LIBRARY_PREFIX})
   endif ()
 
   if(NOT WIN32)
     set(SHARED_FILES src/override/new.cc src/override/malloc.cc)
     add_shim(snmallocshim SHARED ${SHARED_FILES})
     add_shim(snmallocshim-1mib SHARED ${SHARED_FILES})
-    target_compile_definitions(snmallocshim-1mib PRIVATE IS_ADDRESS_SPACE_CONSTRAINED)
+    add_shim(snmallocshim-16mib SHARED ${SHARED_FILES})
+    target_compile_definitions(snmallocshim-16mib PRIVATE SNMALOC_USE_LARGE_CHUNKS)
     # Build a shim with some settings from oe.
     add_shim(snmallocshim-oe SHARED ${SHARED_FILES})
     oe_simulate(snmallocshim-oe)
@@ -260,7 +264,8 @@ if(NOT DEFINED SNMALLOC_ONLY_HEADER_LIBRARY)
   if(SNMALLOC_RUST_SUPPORT)
     add_shim(snmallocshim-rust STATIC src/override/rust.cc)
     add_shim(snmallocshim-1mib-rust STATIC src/override/rust.cc)
-    target_compile_definitions(snmallocshim-1mib-rust PRIVATE IS_ADDRESS_SPACE_CONSTRAINED)
+    add_shim(snmallocshim-16mib-rust STATIC src/override/rust.cc)
+    target_compile_definitions(snmallocshim-16mib-rust PRIVATE SNMALLOC_USE_LARGE_CHUNKS)
   endif()
 
   enable_testing()
@@ -277,8 +282,8 @@ if(NOT DEFINED SNMALLOC_ONLY_HEADER_LIBRARY)
         set(TESTNAME "${TEST_CATEGORY}-${TEST}-${SUPER_SLAB_SIZE}")
 
         add_executable(${TESTNAME} ${SRC})
-        if (${SUPER_SLAB_SIZE} EQUAL 1)
-          target_compile_definitions(${TESTNAME} PRIVATE IS_ADDRESS_SPACE_CONSTRAINED)
+        if (${SUPER_SLAB_SIZE} EQUAL 16)
+          target_compile_definitions(${TESTNAME} PRIVATE SNMALLOC_USE_LARGE_CHUNKS)
         endif()
         if (${SUPER_SLAB_SIZE} EQUAL oe)
           oe_simulate(${TESTNAME})
diff --git a/ci/scripts/test.sh b/ci/scripts/test.sh
index 1d1176e..02e2e65 100755
--- a/ci/scripts/test.sh
+++ b/ci/scripts/test.sh
@@ -4,9 +4,11 @@ cd build
 if [ $SELF_HOST = false ]; then
     ctest -j 4 --output-on-failure -C $BUILD_TYPE
 else
-    sudo cp libsnmallocshim.so libsnmallocshim-1mib.so /usr/local/lib/
+    sudo cp libsnmallocshim.so libsnmallocshim-16mib.so libsnmallocshim-oe.so /usr/local/lib/
     ninja clean
     LD_PRELOAD=/usr/local/lib/libsnmallocshim.so ninja
     ninja clean
-    LD_PRELOAD=/usr/local/lib/libsnmallocshim-1mib.so ninja
+    LD_PRELOAD=/usr/local/lib/libsnmallocshim-16mib.so ninja
+    ninja clean
+    LD_PRELOAD=/usr/local/lib/libsnmallocshim-oe.so ninja
 fi
\ No newline at end of file
diff --git a/src/mem/allocconfig.h b/src/mem/allocconfig.h
index ae6240b..0ea5257 100644
--- a/src/mem/allocconfig.h
+++ b/src/mem/allocconfig.h
@@ -41,29 +41,21 @@ namespace snmalloc
 
   // Specifies smaller slab and super slab sizes for address space
   // constrained scenarios.
-  static constexpr size_t ADDRESS_SPACE_CONSTRAINED =
-#ifdef IS_ADDRESS_SPACE_CONSTRAINED
-    true
-#else
+  static constexpr size_t USE_LARGE_CHUNKS =
+#ifdef SNMALLOC_USE_LARGE_CHUNKS
     // In 32 bit uses smaller superslab.
-    (!bits::is64())
-#endif
-    ;
-
-  // Specifies even smaller slab and super slab sizes for open enclave.
-  static constexpr size_t REALLY_ADDRESS_SPACE_CONSTRAINED =
-#ifdef IS_REALLY_ADDRESS_SPACE_CONSTRAINED
-    true
+    (bits::is64())
 #else
     false
 #endif
     ;
 
-  static constexpr size_t RESERVE_MULTIPLE =
-#ifdef USE_RESERVE_MULTIPLE
-    USE_RESERVE_MULTIPLE
+  // Specifies even smaller slab and super slab sizes for open enclave.
+  static constexpr size_t USE_SMALL_CHUNKS =
+#ifdef SNMALLOC_USE_SMALL_CHUNKS
+    true
 #else
-    bits::is64() ? 16 : 2
+    false
 #endif
     ;
 
@@ -109,9 +101,8 @@ namespace snmalloc
   static constexpr size_t MIN_ALLOC_BITS = bits::ctz_const(MIN_ALLOC_SIZE);
 
   // Slabs are 64 KiB unless constrained to 16 KiB.
-  static constexpr size_t SLAB_BITS = REALLY_ADDRESS_SPACE_CONSTRAINED ?
-    13 :
-    (ADDRESS_SPACE_CONSTRAINED ? 14 : 16);
+  static constexpr size_t SLAB_BITS =
+    USE_SMALL_CHUNKS ? 13 : (USE_LARGE_CHUNKS ? 16 : 14);
   static constexpr size_t SLAB_SIZE = 1 << SLAB_BITS;
   static constexpr size_t SLAB_MASK = ~(SLAB_SIZE - 1);
 
@@ -119,12 +110,11 @@ namespace snmalloc
   // a byte, so the maximum count is 256. This must be a power of two to
   // allow fast masking to find a superslab start address.
   static constexpr size_t SLAB_COUNT_BITS =
-    REALLY_ADDRESS_SPACE_CONSTRAINED ? 5 : (ADDRESS_SPACE_CONSTRAINED ? 6 : 8);
+    USE_SMALL_CHUNKS ? 5 : (USE_LARGE_CHUNKS ? 8 : 6);
   static constexpr size_t SLAB_COUNT = 1 << SLAB_COUNT_BITS;
   static constexpr size_t SUPERSLAB_SIZE = SLAB_SIZE * SLAB_COUNT;
   static constexpr size_t SUPERSLAB_MASK = ~(SUPERSLAB_SIZE - 1);
   static constexpr size_t SUPERSLAB_BITS = SLAB_BITS + SLAB_COUNT_BITS;
-  static constexpr size_t RESERVE_SIZE = SUPERSLAB_SIZE * RESERVE_MULTIPLE;
 
   static_assert((1ULL << SUPERSLAB_BITS) == SUPERSLAB_SIZE, "Sanity check");
 
diff --git a/src/test/func/fixed_region/fixed_region.cc b/src/test/func/fixed_region/fixed_region.cc
index 4f64700..8f25c57 100644
--- a/src/test/func/fixed_region/fixed_region.cc
+++ b/src/test/func/fixed_region/fixed_region.cc
@@ -1,7 +1,6 @@
 #define SNMALLOC_SGX
 #define OPEN_ENCLAVE
 #define OPEN_ENCLAVE_SIMULATION
-#define USE_RESERVE_MULTIPLE 1
 #include <iostream>
 #include <snmalloc.h>
 
diff --git a/src/test/func/two_alloc_types/alloc1.cc b/src/test/func/two_alloc_types/alloc1.cc
index f696600..0f3a9cb 100644
--- a/src/test/func/two_alloc_types/alloc1.cc
+++ b/src/test/func/two_alloc_types/alloc1.cc
@@ -1,9 +1,7 @@
-#undef IS_ADDRESS_SPACE_CONSTRAINED
+#undef SNMALLOC_USE_LARGE_CHUNKS
 #define OPEN_ENCLAVE
 #define OPEN_ENCLAVE_SIMULATION
-#define USE_RESERVE_MULTIPLE 1
 #define NO_BOOTSTRAP_ALLOCATOR
-#define IS_ADDRESS_SPACE_CONSTRAINED
 #define SNMALLOC_EXPOSE_PAGEMAP
 #define SNMALLOC_NAME_MANGLE(a) enclave_##a
 // Redefine the namespace, so we can have two versions.
diff --git a/src/test/func/two_alloc_types/alloc2.cc b/src/test/func/two_alloc_types/alloc2.cc
index 67be116..21316eb 100644
--- a/src/test/func/two_alloc_types/alloc2.cc
+++ b/src/test/func/two_alloc_types/alloc2.cc
@@ -1,6 +1,6 @@
 // Remove parameters feed from test harness
-#undef ADDRESS_SPACE_CONSTRAINED
-#undef REALLY_ADDRESS_SPACE_CONSTRAINED
+#undef SNMALLOC_USE_LARGE_CHUNKS
+#undef SNMALLOC_USE_SMALL_CHUNKS
 
 #define SNMALLOC_NAME_MANGLE(a) host_##a
 #define NO_BOOTSTRAP_ALLOCATOR