diff --git a/libc/src/string/strcmp.h b/libc/src/string/strcmp.h
--- a/libc/src/string/strcmp.h
+++ b/libc/src/string/strcmp.h
@@ -9,11 +9,9 @@
 #ifndef LLVM_LIBC_SRC_STRING_STRCMP_H
 #define LLVM_LIBC_SRC_STRING_STRCMP_H
 
-#include "include/string.h"
-
 namespace __llvm_libc {
 
-int strcmp(const char *l, const char *r);
+int strcmp(const char *left, const char *right);
 
 } // namespace __llvm_libc
 
diff --git a/libc/src/string/strcmp.cpp b/libc/src/string/strcmp.cpp
--- a/libc/src/string/strcmp.cpp
+++ b/libc/src/string/strcmp.cpp
@@ -12,14 +12,12 @@
 
 namespace __llvm_libc {
 
-int LLVM_LIBC_ENTRYPOINT(strcmp)(const char *l, const char *r) {
-  while (*l) {
-    if (*l != *r)
-      break;
-    ++l;
-    ++r;
-  }
-  return *(const unsigned char *)l - *(const unsigned char *)r;
+// TODO: Look at benefits for comparing words at a time.
+int LLVM_LIBC_ENTRYPOINT(strcmp)(const char *left, const char *right) {
+  for (; *left && *left == *right; ++left, ++right)
+    ;
+  return *reinterpret_cast<const unsigned char *>(left) -
+         *reinterpret_cast<const unsigned char *>(right);
 }
 
 } // namespace __llvm_libc
diff --git a/libc/test/src/string/strcmp_test.cpp b/libc/test/src/string/strcmp_test.cpp
--- a/libc/test/src/string/strcmp_test.cpp
+++ b/libc/test/src/string/strcmp_test.cpp
@@ -12,7 +12,11 @@
 TEST(StrCmpTest, EmptyStringsShouldReturnZero) {
   const char *s1 = "";
   const char *s2 = "";
-  const int result = __llvm_libc::strcmp(s1, s2);
+  int result = __llvm_libc::strcmp(s1, s2);
+  ASSERT_EQ(result, 0);
+
+  // Verify operands reversed.
+  result = __llvm_libc::strcmp(s2, s1);
   ASSERT_EQ(result, 0);
 }
 
@@ -33,32 +37,51 @@
 TEST(StrCmpTest, EqualStringsShouldReturnZero) {
   const char *s1 = "abc";
   const char *s2 = "abc";
-  const int result = __llvm_libc::strcmp(s1, s2);
+  int result = __llvm_libc::strcmp(s1, s2);
+  ASSERT_EQ(result, 0);
+
+  // Verify operands reversed.
+  result = __llvm_libc::strcmp(s2, s1);
   ASSERT_EQ(result, 0);
 }
 
 TEST(StrCmpTest, ShouldReturnResultOfFirstDifference) {
   const char *s1 = "___B42__";
   const char *s2 = "___C55__";
-  const int result = __llvm_libc::strcmp(s1, s2);
+  int result = __llvm_libc::strcmp(s1, s2);
   // This should return 'B' - 'C' = -1.
   ASSERT_EQ(result, -1);
+
+  // Verify operands reversed.
+  result = __llvm_libc::strcmp(s2, s1);
+  // This should return 'C' - 'B' = 1.
+  ASSERT_EQ(result, 1);
 }
 
 TEST(StrCmpTest, CapitalizedLetterShouldNotBeEqual) {
   const char *s1 = "abcd";
   const char *s2 = "abCd";
-  const int result = __llvm_libc::strcmp(s1, s2);
+  int result = __llvm_libc::strcmp(s1, s2);
   // 'c' - 'C' = 32.
   ASSERT_EQ(result, 32);
+
+  // Verify operands reversed.
+  result = __llvm_libc::strcmp(s2, s1);
+  // 'C' - 'c' = -32.
+  ASSERT_EQ(result, -32);
 }
 
 TEST(StrCmpTest, UnequalLengthStringsShouldNotReturnZero) {
   const char *s1 = "abc";
   const char *s2 = "abcd";
-  const int result = __llvm_libc::strcmp(s1, s2);
+  int result = __llvm_libc::strcmp(s1, s2);
   // '\0' - 'd' = -100.
   ASSERT_EQ(result, -100);
+
+  // Verify operands reversed.
+  result = __llvm_libc::strcmp(s2, s1);
+  // 'd' - '\0' = 100.
+  ASSERT_EQ(result, 100);
 }
 
 TEST(StrCmpTest, StringArgumentSwapChangesSign) {