diff --git a/src/julia.h b/src/julia.h
index 7bcce4bd07cb4..047611ef65349 100644
--- a/src/julia.h
+++ b/src/julia.h
@@ -19,7 +19,7 @@
 #include <setjmp.h>
 #ifndef _OS_WINDOWS_
 #  define jl_jmp_buf sigjmp_buf
-#  if defined(_CPU_ARM_)
+#  if defined(_CPU_ARM_) || defined(_CPU_PPC_)
 #    define MAX_ALIGN 8
 #  elif defined(_CPU_AARCH64_)
 // int128 is 16 bytes aligned on aarch64
diff --git a/src/julia_internal.h b/src/julia_internal.h
index fcc29f42b1791..db4a2f97383e8 100644
--- a/src/julia_internal.h
+++ b/src/julia_internal.h
@@ -54,6 +54,10 @@ void *jl_gc_perm_alloc(size_t sz);
 static const int jl_gc_sizeclasses[JL_GC_N_POOLS] = {
 #ifdef _P64
     8,
+#elif defined(_CPU_ARM_) || defined(_CPU_PPC_)
+    // ARM and PowerPC has max alignment of 8,
+    // make sure allocation of size 8 has that alignment.
+    4, 8,
 #else
     4, 8, 12,
 #endif
@@ -87,6 +91,10 @@ STATIC_INLINE int JL_CONST_FUNC jl_gc_szclass(size_t sz)
     if (sz <=    8)
         return 0;
     const int N = 0;
+#elif defined(_CPU_ARM_) || defined(_CPU_PPC_)
+    if (sz <=    8)
+        return (sz + 3) / 4 - 1;
+    const int N = 1;
 #else
     if (sz <=   12)
         return (sz + 3) / 4 - 1;
diff --git a/src/julia_threads.h b/src/julia_threads.h
index 50a9bc36c2820..e18eb7283e1d4 100644
--- a/src/julia_threads.h
+++ b/src/julia_threads.h
@@ -55,9 +55,11 @@ typedef struct {
 
     // variables for allocating objects from pools
 #ifdef _P64
-#define JL_GC_N_POOLS 41
+#  define JL_GC_N_POOLS 41
+#elif defined(_CPU_ARM_) || defined(_CPU_PPC_)
+#  define JL_GC_N_POOLS 42
 #else
-#define JL_GC_N_POOLS 43
+#  define JL_GC_N_POOLS 43
 #endif
     jl_gc_pool_t norm_pools[JL_GC_N_POOLS];
 } jl_thread_heap_t;