diff --git a/filecheck/FileCheck.py b/filecheck/FileCheck.py
index 322ac14..1682f1c 100755
--- a/filecheck/FileCheck.py
+++ b/filecheck/FileCheck.py
@@ -264,11 +264,11 @@ def main():
             # CHECK and CHECK-NEXT
             strict_whitespace_match = "" if args.strict_whitespace and args.match_full_lines else " *"
 
-            check_regex = ".*({}):{}(.*)".format(check_prefix, strict_whitespace_match)
+            check_regex = ".*?({}):{}(.*)".format(check_prefix, strict_whitespace_match)
             check_match = re.search(check_regex, line)
             check_type = CheckType.CHECK
             if not check_match:
-                check_regex = ".*({}-NEXT):{}(.*)".format(check_prefix, strict_whitespace_match)
+                check_regex = ".*?({}-NEXT):{}(.*)".format(check_prefix, strict_whitespace_match)
                 check_match = re.search(check_regex, line)
                 check_type = CheckType.CHECK_NEXT
 
diff --git a/tasks.py b/tasks.py
index f85afa1..a10be8d 100644
--- a/tasks.py
+++ b/tasks.py
@@ -18,19 +18,6 @@ def get_os_filename_string():
     assert 0, "error: FileCheck.py could not detect OS"
 
 
-def get_filecheck_py_exec():
-    cwd = os.getcwd()
-    return 'python \\"{cwd}/filecheck/FileCheck.py\\"'.format(cwd=cwd)
-
-
-def get_filecheck_tester_exec():
-    cwd = os.getcwd()
-    os_string = get_os_filename_string()
-
-    template = '\\"{cwd}/tests/integration/tools/FileCheck/FileCheck-9.0.1-{os_string}\\"'
-    return template.format(cwd=cwd, os_string=os_string)
-
-
 def get_filecheck_llvm_path(filecheck_exec):
     cwd = os.getcwd()
     os_string = get_os_filename_string()
@@ -41,11 +28,16 @@ def get_filecheck_llvm_path(filecheck_exec):
     )
 
 
+def get_filecheck_py_exec():
+    cwd = os.getcwd()
+    return 'python \\"{cwd}/filecheck/FileCheck.py\\"'.format(cwd=cwd)
+
+
 def formatted_command(string):
     return re.sub('\\s+', ' ', string).strip()
 
 
-def run_lit_tests(c, filecheck_exec, llvm_only):
+def run_lit_tests(c, filecheck_exec, filecheck_tester_exec, llvm_only):
     assert c
     assert filecheck_exec
     assert llvm_only is not None
@@ -53,7 +45,6 @@ def run_lit_tests(c, filecheck_exec, llvm_only):
     cwd = os.getcwd()
 
     llvm_only_value = "1" if llvm_only else ""
-    filecheck_tester_exec = get_filecheck_tester_exec()
 
     command = formatted_command("""
         lit
@@ -71,11 +62,37 @@ def run_lit_tests(c, filecheck_exec, llvm_only):
     c.run("{}".format(command))
 
 
+@task
+def test_filecheck_llvm(c):
+    filecheck_llvm_8_exec = get_filecheck_llvm_path(FILECHECK_LLVM_8_EXEC)
+    filecheck_llvm_9_exec = get_filecheck_llvm_path(FILECHECK_LLVM_9_EXEC)
+    filecheck_tester_exec = get_filecheck_llvm_path(FILECHECK_LLVM_9_EXEC)
+
+    run_lit_tests(c, filecheck_llvm_8_exec, filecheck_tester_exec, True)
+    run_lit_tests(c, filecheck_llvm_9_exec, filecheck_tester_exec, True)
+
+
+@task
+def test_filecheck_py_using_file_check_llvm_tester(c):
+    filecheck_exec = get_filecheck_py_exec()
+    filecheck_tester_exec = get_filecheck_llvm_path(FILECHECK_LLVM_9_EXEC)
+
+    run_lit_tests(c, filecheck_exec, filecheck_tester_exec, False)
+
+
+@task
+def test_filecheck_py_using_filecheck_py_tester(c):
+    filecheck_exec = get_filecheck_py_exec()
+    filecheck_tester_exec = filecheck_exec
+
+    run_lit_tests(c, filecheck_exec, filecheck_tester_exec, False)
+
+
 @task
 def test(c):
-    run_lit_tests(c, get_filecheck_llvm_path(FILECHECK_LLVM_8_EXEC), True)
-    run_lit_tests(c, get_filecheck_llvm_path(FILECHECK_LLVM_9_EXEC), True)
-    run_lit_tests(c, get_filecheck_py_exec(), False)
+    test_filecheck_llvm(c)
+    test_filecheck_py_using_file_check_llvm_tester(c)
+
 
 @task
 def clean(c):
diff --git a/tests/integration/tests/check_commands/CHECK/one_string/positive-match/05-CHECK-two-times-matches-first/filecheck.check b/tests/integration/tests/check_commands/CHECK/one_string/positive-match/05-CHECK-two-times-matches-first/filecheck.check
new file mode 100644
index 0000000..2a08fcc
--- /dev/null
+++ b/tests/integration/tests/check_commands/CHECK/one_string/positive-match/05-CHECK-two-times-matches-first/filecheck.check
@@ -0,0 +1 @@
+; CHECK:{{^.*filecheck.check:1:(9|10): error: CHECK: expected string not found in input$}}
diff --git a/tests/integration/tests/check_commands/CHECK/one_string/positive-match/05-CHECK-two-times-matches-first/filecheck.input b/tests/integration/tests/check_commands/CHECK/one_string/positive-match/05-CHECK-two-times-matches-first/filecheck.input
new file mode 100644
index 0000000..1350049
--- /dev/null
+++ b/tests/integration/tests/check_commands/CHECK/one_string/positive-match/05-CHECK-two-times-matches-first/filecheck.input
@@ -0,0 +1 @@
+A-very-long-path/filecheck.check:1:9: error: CHECK: expected string not found in input
diff --git a/tests/integration/tests/check_commands/CHECK/one_string/positive-match/05-CHECK-two-times-matches-first/sample.itest b/tests/integration/tests/check_commands/CHECK/one_string/positive-match/05-CHECK-two-times-matches-first/sample.itest
new file mode 100644
index 0000000..ed5ddc6
--- /dev/null
+++ b/tests/integration/tests/check_commands/CHECK/one_string/positive-match/05-CHECK-two-times-matches-first/sample.itest
@@ -0,0 +1 @@
+; RUN: %cat "%S/filecheck.input" | %expect_exit 0 --expect-no-content %FILECHECK_EXEC "%S/filecheck.check"
diff --git a/tests/integration/tests/check_commands/CHECK/two_strings/04-wip-negative_match_second_string/filecheck.check b/tests/integration/tests/check_commands/CHECK/two_strings/04-wip-negative_match_second_string/filecheck.check
new file mode 100644
index 0000000..a3937b2
--- /dev/null
+++ b/tests/integration/tests/check_commands/CHECK/two_strings/04-wip-negative_match_second_string/filecheck.check
@@ -0,0 +1,2 @@
+; CHECK: hello1
+; CHECK: foo
diff --git a/tests/integration/tests/check_commands/CHECK/two_strings/04-wip-negative_match_second_string/filecheck.input b/tests/integration/tests/check_commands/CHECK/two_strings/04-wip-negative_match_second_string/filecheck.input
new file mode 100644
index 0000000..fc94b50
--- /dev/null
+++ b/tests/integration/tests/check_commands/CHECK/two_strings/04-wip-negative_match_second_string/filecheck.input
@@ -0,0 +1,2 @@
+hello1
+hello2
\ No newline at end of file
diff --git a/tests/integration/tests/check_commands/CHECK/two_strings/04-wip-negative_match_second_string/sample.itest b/tests/integration/tests/check_commands/CHECK/two_strings/04-wip-negative_match_second_string/sample.itest
new file mode 100644
index 0000000..69ca0ac
--- /dev/null
+++ b/tests/integration/tests/check_commands/CHECK/two_strings/04-wip-negative_match_second_string/sample.itest
@@ -0,0 +1,12 @@
+; RUN: %cat "%S/filecheck.input" | %expect_exit 1 %FILECHECK_EXEC "%S/filecheck.check" | %FILECHECK_TESTER_EXEC "%s" --match-full-lines
+
+; CHECK: {{.*filecheck.check:2:10: error: CHECK: expected string not found in input$}}
+; CHECK: {{^}}; CHECK: foo{{$}}
+; CHECK: {{^}}         ^{{$}}
+; CHECK: {{^<stdin>:.*:.*: note: scanning from here$}}
+; CHECK: hello2
+; CHECK: ^{{$}}
+; CHECK: {{^<stdin>:.*:.*: note: possible intended match here$}}
+; CHECK: hello2
+; CHECK: ^
+; CHECK-EMPTY:
diff --git a/tests/integration/tests/options/--match-full-lines/CHECK/01_matching_substring_is_rejected_when_full_match_enabled/sample.itest b/tests/integration/tests/options/--match-full-lines/CHECK/01_matching_substring_is_rejected_when_full_match_enabled/sample.itest
index e3266b7..79dfb00 100644
--- a/tests/integration/tests/options/--match-full-lines/CHECK/01_matching_substring_is_rejected_when_full_match_enabled/sample.itest
+++ b/tests/integration/tests/options/--match-full-lines/CHECK/01_matching_substring_is_rejected_when_full_match_enabled/sample.itest
@@ -1,5 +1,5 @@
 ; RUN: %cat "%S/filecheck.input" | %expect_exit 0 --expect-no-content %FILECHECK_EXEC "%S/filecheck.check"
-; RUN: %cat "%S/filecheck.input" | %expect_exit 1 %FILECHECK_EXEC "%S/filecheck.check" --match-full-lines | %FILECHECK_TESTER_EXEC "%s" --match-full-lines --strict-whitespace -check-prefix=OPTION
+; RUN: %cat "%S/filecheck.input" | %expect_exit 1 %FILECHECK_EXEC "%S/filecheck.check" --match-full-lines | %FILECHECK_TESTER_EXEC "%s" --match-full-lines --strict-whitespace --check-prefix=OPTION
 
 ; OPTION:{{^.*}}filecheck.check:1:10: error: CHECK: expected string not found in input{{$}}
 ; OPTION:; CHECK: hello world
diff --git a/tests/integration/tests/options/--strict-whitespace/CHECK/01_input_has_mixed_spaces_and_tabs/sample.itest b/tests/integration/tests/options/--strict-whitespace/CHECK/01_input_has_mixed_spaces_and_tabs/sample.itest
index ac6b271..551666a 100644
--- a/tests/integration/tests/options/--strict-whitespace/CHECK/01_input_has_mixed_spaces_and_tabs/sample.itest
+++ b/tests/integration/tests/options/--strict-whitespace/CHECK/01_input_has_mixed_spaces_and_tabs/sample.itest
@@ -1,5 +1,5 @@
 ; RUN: %cat "%S/filecheck.input" | %expect_exit 0 --expect-no-content %FILECHECK_EXEC "%S/filecheck.check"
-; RUN: %cat "%S/filecheck.input" | %expect_exit 1 %FILECHECK_EXEC "%S/filecheck.check" --strict-whitespace | %FILECHECK_TESTER_EXEC "%s" --match-full-lines -check-prefix=OPTION
+; RUN: %cat "%S/filecheck.input" | %expect_exit 1 %FILECHECK_EXEC "%S/filecheck.check" --strict-whitespace | %FILECHECK_TESTER_EXEC "%s" --match-full-lines --check-prefix=OPTION
 
 ; OPTION: {{^.*}}filecheck.check:1:10: error: CHECK: expected string not found in input{{$}}
 ; OPTION: ; CHECK: hello world hello world
diff --git a/tests/integration/tests/options/--strict-whitespace/CHECK/02_check_has_mixed_spaces_and_tabs/sample.itest b/tests/integration/tests/options/--strict-whitespace/CHECK/02_check_has_mixed_spaces_and_tabs/sample.itest
index 6b705db..fa9134c 100644
--- a/tests/integration/tests/options/--strict-whitespace/CHECK/02_check_has_mixed_spaces_and_tabs/sample.itest
+++ b/tests/integration/tests/options/--strict-whitespace/CHECK/02_check_has_mixed_spaces_and_tabs/sample.itest
@@ -1,5 +1,5 @@
 ; RUN: %cat "%S/filecheck.input" | %expect_exit 0 --expect-no-content %FILECHECK_EXEC "%S/filecheck.check"
-; RUN: %cat "%S/filecheck.input" | %expect_exit 1 %FILECHECK_EXEC "%S/filecheck.check" --strict-whitespace | %FILECHECK_TESTER_EXEC "%s" --strict-whitespace --match-full-lines -check-prefix=OPTION
+; RUN: %cat "%S/filecheck.input" | %expect_exit 1 %FILECHECK_EXEC "%S/filecheck.check" --strict-whitespace | %FILECHECK_TESTER_EXEC "%s" --strict-whitespace --match-full-lines --check-prefix=OPTION
 
 ; OPTION:{{^.*}}filecheck.check:1:10: error: CHECK: expected string not found in input{{$}}
 ; OPTION:; CHECK: hello   world hello  world
diff --git a/tests/integration/tests/options/--strict-whitespace/CHECK_NOT/01_input_has_mixed_spaces_and_tabs/sample.itest b/tests/integration/tests/options/--strict-whitespace/CHECK_NOT/01_input_has_mixed_spaces_and_tabs/sample.itest
index b7c9e99..0977b4e 100644
--- a/tests/integration/tests/options/--strict-whitespace/CHECK_NOT/01_input_has_mixed_spaces_and_tabs/sample.itest
+++ b/tests/integration/tests/options/--strict-whitespace/CHECK_NOT/01_input_has_mixed_spaces_and_tabs/sample.itest
@@ -1,4 +1,4 @@
-; RUN: %cat "%S/filecheck.input" | %expect_exit 1 %FILECHECK_EXEC "%S/filecheck.check" | %FILECHECK_TESTER_EXEC "%s" --strict-whitespace --match-full-lines -check-prefix=NO_OPTION
+; RUN: %cat "%S/filecheck.input" | %expect_exit 1 %FILECHECK_EXEC "%S/filecheck.check" | %FILECHECK_TESTER_EXEC "%s" --strict-whitespace --match-full-lines --check-prefix=NO_OPTION
 ; RUN: %cat "%S/filecheck.input" | %expect_exit 0 --expect-no-content %FILECHECK_EXEC "%S/filecheck.check" --strict-whitespace
 
 ; NO_OPTION:{{^.*}}filecheck.check:1:14: error: CHECK-NOT: excluded string found in input{{$}}
diff --git a/tests/integration/tests/options/--strict-whitespace/CHECK_NOT/02_check_has_mixed_spaces_and_tabs/sample.itest b/tests/integration/tests/options/--strict-whitespace/CHECK_NOT/02_check_has_mixed_spaces_and_tabs/sample.itest
index 6b705db..fa9134c 100644
--- a/tests/integration/tests/options/--strict-whitespace/CHECK_NOT/02_check_has_mixed_spaces_and_tabs/sample.itest
+++ b/tests/integration/tests/options/--strict-whitespace/CHECK_NOT/02_check_has_mixed_spaces_and_tabs/sample.itest
@@ -1,5 +1,5 @@
 ; RUN: %cat "%S/filecheck.input" | %expect_exit 0 --expect-no-content %FILECHECK_EXEC "%S/filecheck.check"
-; RUN: %cat "%S/filecheck.input" | %expect_exit 1 %FILECHECK_EXEC "%S/filecheck.check" --strict-whitespace | %FILECHECK_TESTER_EXEC "%s" --strict-whitespace --match-full-lines -check-prefix=OPTION
+; RUN: %cat "%S/filecheck.input" | %expect_exit 1 %FILECHECK_EXEC "%S/filecheck.check" --strict-whitespace | %FILECHECK_TESTER_EXEC "%s" --strict-whitespace --match-full-lines --check-prefix=OPTION
 
 ; OPTION:{{^.*}}filecheck.check:1:10: error: CHECK: expected string not found in input{{$}}
 ; OPTION:; CHECK: hello   world hello  world