diff --git a/CMakeLists.txt b/CMakeLists.txt
index ec0a5e958..a5aa31814 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -65,6 +65,8 @@ endif()
 set(SNMALLOC_MIN_ALLOC_SIZE "" CACHE STRING "Minimum allocation bytes (power of 2)")
 set(SNMALLOC_MIN_ALLOC_STEP_SIZE "" CACHE STRING "Minimum allocation step (power of 2)")
 
+set(SNMALLOC_PAGESIZE "" CACHE STRING "Page size in bytes")
+
 set(SNMALLOC_DEALLOC_BATCH_RING_ASSOC "" CACHE STRING "Associativity of deallocation batch cache; 0 to disable")
 set(SNMALLOC_DEALLOC_BATCH_RING_SET_BITS "" CACHE STRING "Logarithm of number of deallocation batch cache associativity sets")
 
@@ -257,6 +259,8 @@ add_as_define_value(SNMALLOC_MIN_ALLOC_STEP_SIZE)
 add_as_define_value(SNMALLOC_DEALLOC_BATCH_RING_ASSOC)
 add_as_define_value(SNMALLOC_DEALLOC_BATCH_RING_SET_BITS)
 
+add_as_define_value(SNMALLOC_PAGESIZE)
+
 target_compile_definitions(snmalloc INTERFACE $<$<BOOL:CONST_QUALIFIED_MALLOC_USABLE_SIZE>:MALLOC_USABLE_SIZE_QUALIFIER=const>)
 
 # In debug and CI builds, link the backtrace library so that we can get stack
diff --git a/src/snmalloc/pal/pal_posix.h b/src/snmalloc/pal/pal_posix.h
index 097d18f61..2685ba9f4 100644
--- a/src/snmalloc/pal/pal_posix.h
+++ b/src/snmalloc/pal/pal_posix.h
@@ -8,6 +8,7 @@
 #endif
 #include <errno.h>
 #include <fcntl.h>
+#include <limits.h>
 #include <stdio.h>
 #include <string.h>
 #include <strings.h>
@@ -129,8 +130,15 @@ namespace snmalloc
       | Entropy
 #endif
       ;
-
+#ifdef SNMALLOC_PAGESIZE
+    static_assert(
+      bits::is_pow2(SNMALLOC_PAGESIZE), "Page size must be a power of 2");
+    static constexpr size_t page_size = SNMALLOC_PAGESIZE;
+#elif defined(PAGESIZE)
+    static constexpr size_t page_size = max(Aal::smallest_page_size, PAGESIZE);
+#else
     static constexpr size_t page_size = Aal::smallest_page_size;
+#endif
 
     /**
      * Address bits are potentially mediated by some POSIX OSes, but generally