diff --git a/compiler-rt/test/asan/TestCases/strncasecmp_strict.c b/compiler-rt/test/asan/TestCases/strncasecmp_strict.c
new file mode 100644
index 000000000000..aa658402b42b
--- /dev/null
+++ b/compiler-rt/test/asan/TestCases/strncasecmp_strict.c
@@ -0,0 +1,67 @@
+// Test strict_string_checks option in strncmp function
+// RUN: %clang_asan %s -o %t
+
+// RUN: %env_asan_opts=strict_string_checks=false %run %t a 2>&1
+// RUN: %env_asan_opts=strict_string_checks=true %run %t a 2>&1
+// RUN: not %run %t b 2>&1 | FileCheck %s
+// RUN: not %run %t c 2>&1 | FileCheck %s
+// RUN: not %run %t d 2>&1 | FileCheck %s
+// RUN: not %run %t e 2>&1 | FileCheck %s
+// RUN: not %run %t f 2>&1 | FileCheck %s
+// RUN: not %run %t g 2>&1 | FileCheck %s
+// RUN: %env_asan_opts=strict_string_checks=false %run %t h 2>&1
+// RUN: %env_asan_opts=strict_string_checks=true not %run %t h 2>&1 | FileCheck %s
+// RUN: %env_asan_opts=strict_string_checks=false %run %t i 2>&1
+// RUN: %env_asan_opts=strict_string_checks=true not %run %t i 2>&1 | FileCheck %s
+
+// XFAIL: win32
+
+#include <assert.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+
+int main(int argc, char **argv) {
+  assert(argc >= 2);
+  const size_t size = 100;
+  char fill = 'o';
+  char s1[size];
+  char s2[size];
+  memset(s1, fill, size);
+  memset(s2, fill, size);
+
+  switch (argv[1][0]) {
+    case 'a':
+      s1[size - 1] = 'z';
+      s2[size - 1] = 'x';
+      for (int i = 0; i <= size; ++i)
+        assert((strncasecmp(s1, s2, i) == 0) == (i < size));
+      s1[size - 1] = '\0';
+      s2[size - 1] = '\0';
+      assert(strncasecmp(s1, s2, 2*size) == 0);
+      break;
+    case 'b':
+      return strncasecmp(s1-1, s2, 1);
+    case 'c':
+      return strncasecmp(s1, s2-1, 1);
+    case 'd':
+      return strncasecmp(s1+size, s2, 1);
+    case 'e':
+      return strncasecmp(s1, s2+size, 1);
+    case 'f':
+      return strncasecmp(s1+1, s2, size);
+    case 'g':
+      return strncasecmp(s1, s2+1, size);
+    case 'h':
+      s1[size - 1] = '\0';
+      assert(strncasecmp(s1, s2, 2*size) != 0);
+      break;
+    case 'i':
+      s2[size - 1] = '\0';
+      assert(strncasecmp(s1, s2, 2*size) != 0);
+      break;
+    // CHECK: {{.*}}ERROR: AddressSanitizer: stack-buffer-{{ov|und}}erflow on address
+  }
+  return 0;
+}
diff --git a/compiler-rt/test/asan/TestCases/strncmp_strict.c b/compiler-rt/test/asan/TestCases/strncmp_strict.c
index 5eb3069c077b..5b5429064ced 100644
--- a/compiler-rt/test/asan/TestCases/strncmp_strict.c
+++ b/compiler-rt/test/asan/TestCases/strncmp_strict.c
@@ -14,19 +14,6 @@
 // RUN: %env_asan_opts=strict_string_checks=false %run %t i 2>&1
 // RUN: %env_asan_opts=strict_string_checks=true not %run %t i 2>&1 | FileCheck %s
 
-// RUN: %env_asan_opts=strict_string_checks=false %run %t A 2>&1
-// RUN: %env_asan_opts=strict_string_checks=true %run %t A 2>&1
-// RUN: not %run %t B 2>&1 | FileCheck %s
-// RUN: not %run %t C 2>&1 | FileCheck %s
-// RUN: not %run %t D 2>&1 | FileCheck %s
-// RUN: not %run %t E 2>&1 | FileCheck %s
-// RUN: not %run %t F 2>&1 | FileCheck %s
-// RUN: not %run %t G 2>&1 | FileCheck %s
-// RUN: %env_asan_opts=strict_string_checks=false %run %t H 2>&1
-// RUN: %env_asan_opts=strict_string_checks=true not %run %t H 2>&1 | FileCheck %s
-// RUN: %env_asan_opts=strict_string_checks=false %run %t I 2>&1
-// RUN: %env_asan_opts=strict_string_checks=true not %run %t I 2>&1 | FileCheck %s
-
 #include <assert.h>
 #include <stdlib.h>
 #include <stdio.h>
@@ -42,38 +29,35 @@ int main(int argc, char **argv) {
   memset(s1, fill, size);
   memset(s2, fill, size);
 
-  int (*cmp_fn)(const char *, const char *, size_t);
-  cmp_fn = islower(argv[1][0]) ? &strncmp : &strncasecmp;
-
-  switch(tolower(argv[1][0])) {
+  switch (argv[1][0]) {
     case 'a':
       s1[size - 1] = 'z';
       s2[size - 1] = 'x';
       for (int i = 0; i <= size; ++i)
-        assert((cmp_fn(s1, s2, i) == 0) == (i < size));
+        assert((strncmp(s1, s2, i) == 0) == (i < size));
       s1[size - 1] = '\0';
       s2[size - 1] = '\0';
-      assert(cmp_fn(s1, s2, 2*size) == 0);
+      assert(strncmp(s1, s2, 2*size) == 0);
       break;
     case 'b':
-      return cmp_fn(s1-1, s2, 1);
+      return strncmp(s1-1, s2, 1);
     case 'c':
-      return cmp_fn(s1, s2-1, 1);
+      return strncmp(s1, s2-1, 1);
     case 'd':
-      return cmp_fn(s1+size, s2, 1);
+      return strncmp(s1+size, s2, 1);
     case 'e':
-      return cmp_fn(s1, s2+size, 1);
+      return strncmp(s1, s2+size, 1);
     case 'f':
-      return cmp_fn(s1+1, s2, size);
+      return strncmp(s1+1, s2, size);
     case 'g':
-      return cmp_fn(s1, s2+1, size);
+      return strncmp(s1, s2+1, size);
     case 'h':
       s1[size - 1] = '\0';
-      assert(cmp_fn(s1, s2, 2*size) != 0);
+      assert(strncmp(s1, s2, 2*size) != 0);
       break;
     case 'i':
       s2[size - 1] = '\0';
-      assert(cmp_fn(s1, s2, 2*size) != 0);
+      assert(strncmp(s1, s2, 2*size) != 0);
       break;
     // CHECK: {{.*}}ERROR: AddressSanitizer: stack-buffer-{{ov|und}}erflow on address
   }