diff --git a/combined.h b/combined.h
index 922c2e5..371fb78 100644
--- a/combined.h
+++ b/combined.h
@@ -920,7 +920,7 @@
     if (!Depot->find(Hash, &RingPos, &Size))
       return;
     for (unsigned I = 0; I != Size && I != MaxTraceSize; ++I)
-      Trace[I] = (*Depot)[RingPos + I];
+      Trace[I] = static_cast<uintptr_t>((*Depot)[RingPos + I]);
   }
 
   static void getErrorInfo(struct scudo_error_info *ErrorInfo,
diff --git a/internal_defs.h b/internal_defs.h
index c9ffad1..621fc9c 100644
--- a/internal_defs.h
+++ b/internal_defs.h
@@ -78,16 +78,16 @@
 
 namespace scudo {
 
-typedef unsigned long uptr;
-typedef unsigned char u8;
-typedef unsigned short u16;
-typedef unsigned int u32;
-typedef unsigned long long u64;
-typedef signed long sptr;
-typedef signed char s8;
-typedef signed short s16;
-typedef signed int s32;
-typedef signed long long s64;
+typedef uintptr_t uptr;
+typedef uint8_t u8;
+typedef uint16_t u16;
+typedef uint32_t u32;
+typedef uint64_t u64;
+typedef intptr_t sptr;
+typedef int8_t s8;
+typedef int16_t s16;
+typedef int32_t s32;
+typedef int64_t s64;
 
 // The following two functions have platform specific implementations.
 void outputRaw(const char *Buffer);
diff --git a/secondary.h b/secondary.h
index 630e64d..aa50fa9 100644
--- a/secondary.h
+++ b/secondary.h
@@ -485,7 +485,7 @@
                                      FillContentsMode FillContents) {
   if (Options.get(OptionBit::AddLargeAllocationSlack))
     Size += 1UL << SCUDO_MIN_ALIGNMENT_LOG;
-  Alignment = Max(Alignment, 1UL << SCUDO_MIN_ALIGNMENT_LOG);
+  Alignment = Max(Alignment, uptr(1U) << SCUDO_MIN_ALIGNMENT_LOG);
   const uptr PageSize = getPageSizeCached();
   uptr RoundedSize =
       roundUpTo(roundUpTo(Size, Alignment) + LargeBlock::getHeaderSize() +
diff --git a/wrappers_c_checks.h b/wrappers_c_checks.h
index 7fc1a96..ec9c1a1 100644
--- a/wrappers_c_checks.h
+++ b/wrappers_c_checks.h
@@ -46,8 +46,10 @@
 // builtin supported by recent clang & GCC if it exists, otherwise fallback to a
 // costly division.
 inline bool checkForCallocOverflow(uptr Size, uptr N, uptr *Product) {
-#if __has_builtin(__builtin_umull_overflow)
+#if __has_builtin(__builtin_umull_overflow) && (SCUDO_WORDSIZE == 64U)
   return __builtin_umull_overflow(Size, N, Product);
+#elif __has_builtin(__builtin_umul_overflow) && (SCUDO_WORDSIZE == 32U)
+  return __builtin_umul_overflow(Size, N, Product);
 #else
   *Product = Size * N;
   if (!Size)