diff --git a/src/s390/simulator-s390.cc b/src/s390/simulator-s390.cc
index dda51e205d..74d37bc20a 100644
--- a/src/s390/simulator-s390.cc
+++ b/src/s390/simulator-s390.cc
@@ -5700,15 +5700,15 @@ void Simulator::CallInternal(byte* entry, int reg_arg_count) {
 // Check that the non-volatile registers have been preserved.
 #ifndef V8_TARGET_ARCH_S390X
   if (reg_arg_count < 5) {
-    DCHECK_EQ(callee_saved_value + 6, get_low_register<int32_t>(r6));
+    DCHECK_EQ(callee_saved_value + 6, get_low_register<uint32_t>(r6));
   }
-  DCHECK_EQ(callee_saved_value + 7, get_low_register<int32_t>(r7));
-  DCHECK_EQ(callee_saved_value + 8, get_low_register<int32_t>(r8));
-  DCHECK_EQ(callee_saved_value + 9, get_low_register<int32_t>(r9));
-  DCHECK_EQ(callee_saved_value + 10, get_low_register<int32_t>(r10));
-  DCHECK_EQ(callee_saved_value + 11, get_low_register<int32_t>(r11));
-  DCHECK_EQ(callee_saved_value + 12, get_low_register<int32_t>(r12));
-  DCHECK_EQ(callee_saved_value + 13, get_low_register<int32_t>(r13));
+  DCHECK_EQ(callee_saved_value + 7, get_low_register<uint32_t>(r7));
+  DCHECK_EQ(callee_saved_value + 8, get_low_register<uint32_t>(r8));
+  DCHECK_EQ(callee_saved_value + 9, get_low_register<uint32_t>(r9));
+  DCHECK_EQ(callee_saved_value + 10, get_low_register<uint32_t>(r10));
+  DCHECK_EQ(callee_saved_value + 11, get_low_register<uint32_t>(r11));
+  DCHECK_EQ(callee_saved_value + 12, get_low_register<uint32_t>(r12));
+  DCHECK_EQ(callee_saved_value + 13, get_low_register<uint32_t>(r13));
 #else
   if (reg_arg_count < 5) {
     DCHECK_EQ(callee_saved_value + 6, get_register(r6));
@@ -5816,15 +5816,15 @@ intptr_t Simulator::Call(byte* entry, int argument_count, ...) {
 // Check that the non-volatile registers have been preserved.
 #ifndef V8_TARGET_ARCH_S390X
   if (reg_arg_count < 5) {
-    DCHECK_EQ(callee_saved_value + 6, get_low_register<int32_t>(r6));
+    DCHECK_EQ(callee_saved_value + 6, get_low_register<uint32_t>(r6));
   }
-  DCHECK_EQ(callee_saved_value + 7, get_low_register<int32_t>(r7));
-  DCHECK_EQ(callee_saved_value + 8, get_low_register<int32_t>(r8));
-  DCHECK_EQ(callee_saved_value + 9, get_low_register<int32_t>(r9));
-  DCHECK_EQ(callee_saved_value + 10, get_low_register<int32_t>(r10));
-  DCHECK_EQ(callee_saved_value + 11, get_low_register<int32_t>(r11));
-  DCHECK_EQ(callee_saved_value + 12, get_low_register<int32_t>(r12));
-  DCHECK_EQ(callee_saved_value + 13, get_low_register<int32_t>(r13));
+  DCHECK_EQ(callee_saved_value + 7, get_low_register<uint32_t>(r7));
+  DCHECK_EQ(callee_saved_value + 8, get_low_register<uint32_t>(r8));
+  DCHECK_EQ(callee_saved_value + 9, get_low_register<uint32_t>(r9));
+  DCHECK_EQ(callee_saved_value + 10, get_low_register<uint32_t>(r10));
+  DCHECK_EQ(callee_saved_value + 11, get_low_register<uint32_t>(r11));
+  DCHECK_EQ(callee_saved_value + 12, get_low_register<uint32_t>(r12));
+  DCHECK_EQ(callee_saved_value + 13, get_low_register<uint32_t>(r13));
 #else
   if (reg_arg_count < 5) {
     DCHECK_EQ(callee_saved_value + 6, get_register(r6));
@@ -5850,7 +5850,7 @@ intptr_t Simulator::Call(byte* entry, int argument_count, ...) {
 // Pop stack passed arguments.
 
 #ifndef V8_TARGET_ARCH_S390X
-  DCHECK_EQ(entry_stack, get_low_register<int32_t>(sp));
+  DCHECK_EQ(entry_stack, get_low_register<uint32_t>(sp));
 #else
   DCHECK_EQ(entry_stack, get_register(sp));
 #endif