diff --git a/src/mono/mono/mini/cpu-ppc64.mdesc b/src/mono/mono/mini/cpu-ppc64.mdesc
index d2437a34fda45e..77d99656d72151 100644
--- a/src/mono/mono/mini/cpu-ppc64.mdesc
+++ b/src/mono/mono/mini/cpu-ppc64.mdesc
@@ -45,18 +45,18 @@
 #
 # See the code in mini-x86.c for more details on how the specifiers are used.
 #
-tailcall: len:124 clob:c
+tailcall: len:152 clob:c
 tailcall_parameter: len:0 # PowerPC outputs a nice fixed size memcpy loop for larger stack_usage, so 0.
 memory_barrier: len:4
 nop: len:4
 relaxed_nop: len:4
-break: len:40
+break: len:44
 seq_point: len:48
 il_seq_point: len:0
-call: dest:a clob:c len:36
+call: dest:a clob:c len:40
 br: len:4
-throw: src1:i len:40
-rethrow: src1:i len:40
+throw: src1:i len:44
+rethrow: src1:i len:44
 ckfinite: dest:f src1:f
 ppc_check_finite: src1:i len:16
 add_ovf_carry: dest:i src1:i src2:i len:16
@@ -77,16 +77,16 @@ fcompare: src1:f src2:f len:12
 arglist: src1:i len:12
 setlret: src1:i src2:i len:12
 check_this: src1:b len:4
-voidcall: len:36 clob:c
+voidcall: len:40 clob:c
 voidcall_reg: src1:i len:16 clob:c
 voidcall_membase: src1:b len:16 clob:c
-fcall: dest:g len:36 clob:c
+fcall: dest:g len:40 clob:c
 fcall_reg: dest:g src1:i len:16 clob:c
 fcall_membase: dest:g src1:b len:16 clob:c
-lcall: dest:a len:36 clob:c
+lcall: dest:a len:40 clob:c
 lcall_reg: dest:a src1:i len:16 clob:c
 lcall_membase: dest:a src1:b len:16 clob:c
-vcall: len:16 clob:c
+vcall: len:20 clob:c
 vcall_reg: src1:i len:16 clob:c
 vcall_membase: src1:b len:12 clob:c
 call_reg: dest:a src1:i len:16 clob:c
@@ -404,7 +404,7 @@ int_max_un: dest:i src1:i src2:i len:8 clob:1
 
 #long_conv_to_ovf_i4_2: dest:i src1:i src2:i len:30
 
-vcall2: len:36 clob:c
+vcall2: len:40 clob:c
 vcall2_reg: src1:i len:16 clob:c
 vcall2_membase: src1:b len:16 clob:c
 
diff --git a/src/mono/mono/mini/mini-ppc.c b/src/mono/mono/mini/mini-ppc.c
index 93abd63562ff53..cf8f045f992371 100644
--- a/src/mono/mono/mini/mini-ppc.c
+++ b/src/mono/mono/mini/mini-ppc.c
@@ -5142,8 +5142,8 @@ mono_arch_emit_prolog (MonoCompile *cfg)
 				int soffset = 0;
 				int cur_reg;
 				int size = 0;
-				g_assert (ppc_is_imm16 (inst->inst_offset));
-				g_assert (ppc_is_imm16 (inst->inst_offset + ainfo->vtregs * sizeof (target_mgreg_t)));
+				g_assert (ppc_is_imm32 (inst->inst_offset));
+				g_assert (ppc_is_imm32 (inst->inst_offset + ainfo->vtregs * sizeof (target_mgreg_t)));
 				/* FIXME: what if there is no class? */
 				if (sig->pinvoke && !sig->marshalling_disabled && mono_class_from_mono_type_internal (inst->inst_vtype))
 					size = mono_class_native_size (mono_class_from_mono_type_internal (inst->inst_vtype), NULL);
@@ -5171,21 +5171,39 @@ mono_arch_emit_prolog (MonoCompile *cfg)
 						                         (sizeof (target_mgreg_t) - ainfo->bytes) * 8);
 							ppc_stptr (code, ppc_r0, doffset, inst->inst_basereg);
 #else
-							if (mono_class_native_size (inst->klass, NULL) == 1) {
-							  ppc_stb (code, ainfo->reg + cur_reg, doffset, inst->inst_basereg);
-							} else if (mono_class_native_size (inst->klass, NULL) == 2) {
-								ppc_sth (code, ainfo->reg + cur_reg, doffset, inst->inst_basereg);
-							} else if (mono_class_native_size (inst->klass, NULL) == 4) {  // WDS -- maybe <=4?
-								ppc_stw (code, ainfo->reg + cur_reg, doffset, inst->inst_basereg);
-							} else {
-								ppc_stptr (code, ainfo->reg + cur_reg, doffset, inst->inst_basereg);  // WDS -- Better way?
+							if (ppc_is_imm16 (inst->inst_offset)) {
+								if (mono_class_native_size (inst->klass, NULL) == 1) {
+								ppc_stb (code, ainfo->reg + cur_reg, doffset, inst->inst_basereg);
+								} else if (mono_class_native_size (inst->klass, NULL) == 2) {
+									ppc_sth (code, ainfo->reg + cur_reg, doffset, inst->inst_basereg);
+								} else if (mono_class_native_size (inst->klass, NULL) == 4) {  // WDS -- maybe <=4?
+									ppc_stw (code, ainfo->reg + cur_reg, doffset, inst->inst_basereg);
+								} else {
+									ppc_stptr (code, ainfo->reg + cur_reg, doffset, inst->inst_basereg);  // WDS -- Better way?
+								}
+							}
+							else if (ppc_is_imm32 (inst->inst_offset)) {
+								ppc_addis (code, ppc_r12, inst->inst_basereg, ppc_ha(doffset));
+								ppc_stptr (code, ainfo->reg + cur_reg, doffset, ppc_r12);
+							}
+							else {
+								g_assert_not_reached();
 							}
 #endif
 						} else
 #endif
 						{
-							ppc_stptr (code, ainfo->reg + cur_reg, doffset,
-									inst->inst_basereg);
+							if (ppc_is_imm16 (inst->inst_offset)) {
+								ppc_stptr (code, ainfo->reg + cur_reg, doffset,
+										inst->inst_basereg);
+							}
+							else if (ppc_is_imm32 (inst->inst_offset)) {
+								ppc_addis (code, ppc_r12, inst->inst_basereg, ppc_ha(doffset));
+								ppc_stptr (code, ainfo->reg + cur_reg, doffset, ppc_r12);
+							}
+							else {
+								g_assert_not_reached();
+							}
 						}
 					}
 					soffset += sizeof (target_mgreg_t);