diff --git a/compiler-rt/lib/scudo/standalone/internal_defs.h b/compiler-rt/lib/scudo/standalone/internal_defs.h
--- a/compiler-rt/lib/scudo/standalone/internal_defs.h
+++ b/compiler-rt/lib/scudo/standalone/internal_defs.h
@@ -105,14 +105,11 @@
 
 void NORETURN reportCheckFailed(const char *File, int Line,
                                 const char *Condition, u64 Value1, u64 Value2);
-
 #define CHECK_IMPL(C1, Op, C2)                                                 \
   do {                                                                         \
-    scudo::u64 V1 = (scudo::u64)(C1);                                          \
-    scudo::u64 V2 = (scudo::u64)(C2);                                          \
-    if (UNLIKELY(!(V1 Op V2))) {                                               \
-      scudo::reportCheckFailed(__FILE__, __LINE__,                             \
-                               "(" #C1 ") " #Op " (" #C2 ")", V1, V2);         \
+    if (UNLIKELY(!(C1 Op C2))) {                                               \
+      scudo::reportCheckFailed(__FILE__, __LINE__, #C1 " " #Op " " #C2,        \
+                               (scudo::u64)C1, (scudo::u64)C2);                \
       scudo::die();                                                            \
     }                                                                          \
   } while (false)
diff --git a/compiler-rt/lib/scudo/standalone/report.cpp b/compiler-rt/lib/scudo/standalone/report.cpp
--- a/compiler-rt/lib/scudo/standalone/report.cpp
+++ b/compiler-rt/lib/scudo/standalone/report.cpp
@@ -45,8 +45,8 @@
     trap();
   }
   ScopedErrorReport Report;
-  Report.append("CHECK failed @ %s:%d %s (%llu, %llu)\n", File, Line, Condition,
-                Value1, Value2);
+  Report.append("CHECK failed @ %s:%d %s ((u64)op1=%llu, (u64)op2=%llu)\n",
+                File, Line, Condition, Value1, Value2);
 }
 
 // Generic string fatal error message.
diff --git a/compiler-rt/lib/scudo/standalone/tests/report_test.cpp b/compiler-rt/lib/scudo/standalone/tests/report_test.cpp
--- a/compiler-rt/lib/scudo/standalone/tests/report_test.cpp
+++ b/compiler-rt/lib/scudo/standalone/tests/report_test.cpp
@@ -10,6 +10,13 @@
 
 #include "report.h"
 
+TEST(ScudoReportTest, Check) {
+  CHECK_LT(-1, 1);
+  EXPECT_DEATH(CHECK_GT(-1, 1),
+               "\\(-1\\) > \\(1\\) \\(\\(u64\\)op1=18446744073709551615, "
+               "\\(u64\\)op2=1");
+}
+
 TEST(ScudoReportTest, Generic) {
   // Potentially unused if EXPECT_DEATH isn't defined.
   UNUSED void *P = reinterpret_cast<void *>(0x42424242U);