diff --git a/numpy/core/include/numpy/npy_cpu.h b/numpy/core/include/numpy/npy_cpu.h
index 5edd8f42e..31560eac3 100644
--- a/numpy/core/include/numpy/npy_cpu.h
+++ b/numpy/core/include/numpy/npy_cpu.h
@@ -102,6 +102,8 @@
     #define NPY_CPU_ARCEB
 #elif defined(__riscv) && defined(__riscv_xlen) && __riscv_xlen == 64
     #define NPY_CPU_RISCV64
+#elif defined(__EMSCRIPTEN__)
+    #define NPY_CPU_EMSCRIPTEN
 #else
     #error Unknown CPU, please report this to numpy maintainers with \
     information about your platform (OS, CPU and compiler)
diff --git a/numpy/core/include/numpy/npy_endian.h b/numpy/core/include/numpy/npy_endian.h
index 649bdb0a6..ec2f6eda5 100644
--- a/numpy/core/include/numpy/npy_endian.h
+++ b/numpy/core/include/numpy/npy_endian.h
@@ -47,7 +47,8 @@
             || defined(NPY_CPU_MIPSEL)  \
             || defined(NPY_CPU_PPC64LE) \
             || defined(NPY_CPU_ARCEL)   \
-            || defined(NPY_CPU_RISCV64)
+            || defined(NPY_CPU_RISCV64) \
+            || defined(NPY_CPU_EMSCRIPTEN)
         #define NPY_BYTE_ORDER NPY_LITTLE_ENDIAN
     #elif defined(NPY_CPU_PPC)          \
             || defined(NPY_CPU_SPARC)   \