diff --git a/crypto/func/auto-tests/run_tests.js b/crypto/func/auto-tests/run_tests.js
index 28a0d536..bef2ed42 100644
--- a/crypto/func/auto-tests/run_tests.js
+++ b/crypto/func/auto-tests/run_tests.js
@@ -92,6 +92,9 @@ class CompareOutputError extends Error {
 class CompareFifCodegenError extends Error {
 }
 
+class CompareCodeHashError extends Error {
+}
+
 
 /*
  * In positive tests, there are several testcases "input X should produce output Y".
@@ -236,6 +239,22 @@ class FuncTestCaseFifCodegen {
     }
 }
 
+/*
+ * @code_hash checks that hash of compiled output.fif matches the provided value.
+ * It's used to "record" code boc hash and to check that it remains the same on compiler modifications.
+ * Being much less flexible than @fif_codegen, it nevertheless gives a guarantee of bytecode stability.
+ */
+class FuncTestCaseExpectedHash {
+    constructor(/**string*/ expected_hash) {
+        this.code_hash = expected_hash
+    }
+
+    check(fif_code_hash) {
+        if (this.code_hash !== fif_code_hash)
+            throw new CompareCodeHashError(`expected ${this.code_hash}, actual ${fif_code_hash}`)
+    }
+}
+
 
 class FuncTestFile {
     constructor(/**string*/ func_filename, /**string*/ artifacts_folder) {
@@ -249,6 +268,8 @@ class FuncTestFile {
         this.input_output = []
         /** @type {FuncTestCaseFifCodegen[]} */
         this.fif_codegen = []
+        /** @type {FuncTestCaseExpectedHash | null} */
+        this.expected_hash = null
     }
 
     parse_input_from_func_file() {
@@ -270,6 +291,8 @@ class FuncTestFile {
                 this.fif_codegen.push(new FuncTestCaseFifCodegen(this.parse_string_value(lines), true))
             } else if (line.startsWith("@fif_codegen")) {
                 this.fif_codegen.push(new FuncTestCaseFifCodegen(this.parse_string_value(lines), false))
+            } else if (line.startsWith("@code_hash")) {
+                this.expected_hash = new FuncTestCaseExpectedHash(this.parse_string_value(lines, false)[0])
             }
             this.line_idx++
         }
@@ -281,7 +304,7 @@ class FuncTestFile {
     }
 
     /** @return {string[]} */
-    parse_string_value(/**string[]*/ lines) {
+    parse_string_value(/**string[]*/ lines, allow_multiline = true) {
         // a tag must be followed by a space (single-line), e.g. '@stderr some text'
         // or be a multi-line value, surrounded by """
         const line = lines[this.line_idx]
@@ -292,6 +315,8 @@ class FuncTestFile {
             throw new ParseInputError(`${line} value is empty (not followed by a string or a multiline """)`)
         if (is_single_line && is_multi_line)
             throw new ParseInputError(`${line.substring(0, pos_sp)} value is both single-line and followed by """`)
+        if (is_multi_line && !allow_multiline)
+            throw new ParseInputError(`${line} value should be single-line`);
 
         if (is_single_line)
             return [line.substring(pos_sp + 1).trim()]
@@ -337,6 +362,8 @@ class FuncTestFile {
             let runner = `"${this.get_compiled_fif_filename()}" include <s constant code\n`
             for (let t of this.input_output)
                 runner += `${t.input} ${t.method_id} code 1 runvmx abort"exitcode is not 0" .s cr { drop } depth 1- times\n`
+            if (this.expected_hash !== null)
+                runner += `"${this.get_compiled_fif_filename()}" include hash .s\n`
             fs.writeFileSync(this.get_runner_fif_filename(), runner)
         }
 
@@ -345,6 +372,11 @@ class FuncTestFile {
         stderr = (res.stderr || res.error).toString()
         stdout = (res.stdout || '').toString()
         let stdout_lines = stdout.split("\n").map(x => x.trim()).filter(s => s.length > 0)
+        let fif_code_hash = null
+        if (this.expected_hash !== null) { // then the last stdout line is a hash
+            fif_code_hash = stdout_lines[stdout_lines.length - 1]
+            stdout_lines = stdout_lines.slice(0, stdout_lines.length - 1)
+        }
 
         if (exit_code)
             throw new FiftExecutionFailedError(`fift exit_code = ${exit_code}`, stderr)
@@ -360,6 +392,9 @@ class FuncTestFile {
             for (let fif_codegen of this.fif_codegen)
                 fif_codegen.check(fif_output)
         }
+
+        if (this.expected_hash !== null)
+            this.expected_hash.check(fif_code_hash)
     }
 }
 
@@ -408,6 +443,10 @@ async function run_all_tests(/**string[]*/ tests) {
                 print("  Was compiled to:", testcase.get_compiled_fif_filename())
                 print(fs.readFileSync(testcase.get_compiled_fif_filename(), 'utf-8'))
                 process.exit(2)
+            } else if (e instanceof CompareCodeHashError) {
+                print("  Mismatch in code hash:", e.message)
+                print("  Was compiled to:", testcase.get_compiled_fif_filename())
+                process.exit(2)
             }
             throw e
         }
diff --git a/crypto/func/auto-tests/run_tests.py b/crypto/func/auto-tests/run_tests.py
index 3e2cb8a6..e9e393e2 100644
--- a/crypto/func/auto-tests/run_tests.py
+++ b/crypto/func/auto-tests/run_tests.py
@@ -88,6 +88,10 @@ class CompareFifCodegenError(Exception):
     pass
 
 
+class CompareCodeHashError(Exception):
+    pass
+
+
 class FuncTestCaseInputOutput:
     """
     In positive tests, there are several testcases "input X should produce output Y".
@@ -226,6 +230,21 @@ class FuncTestCaseFifCodegen:
         return cmd_pattern == cmd_output and (comment_pattern is None or comment_pattern == comment_output)
 
 
+class FuncTestCaseExpectedHash:
+    """
+    @code_hash checks that hash of compiled output.fif matches the provided value.
+    It's used to "record" code boc hash and to check that it remains the same on compiler modifications.
+    Being much less flexible than @fif_codegen, it nevertheless gives a guarantee of bytecode stability.
+    """
+
+    def __init__(self, expected_hash: str):
+        self.code_hash = expected_hash
+
+    def check(self, fif_code_hash: str):
+        if self.code_hash != fif_code_hash:
+            raise CompareCodeHashError("expected %s, actual %s" % (self.code_hash, fif_code_hash))
+
+
 class FuncTestFile:
     def __init__(self, func_filename: str, artifacts_folder: str):
         self.line_idx = 0
@@ -235,6 +254,7 @@ class FuncTestFile:
         self.stderr_includes: list[FuncTestCaseStderr] = []
         self.input_output: list[FuncTestCaseInputOutput] = []
         self.fif_codegen: list[FuncTestCaseFifCodegen] = []
+        self.expected_hash: FuncTestCaseExpectedHash | None = None
 
     def parse_input_from_func_file(self):
         with open(self.func_filename, "r") as fd:
@@ -256,6 +276,8 @@ class FuncTestFile:
                 self.fif_codegen.append(FuncTestCaseFifCodegen(self.parse_string_value(lines), True))
             elif line.startswith("@fif_codegen"):
                 self.fif_codegen.append(FuncTestCaseFifCodegen(self.parse_string_value(lines), False))
+            elif line.startswith("@code_hash"):
+                self.expected_hash = FuncTestCaseExpectedHash(self.parse_string_value(lines, False)[0])
             self.line_idx = self.line_idx + 1
 
         if len(self.input_output) == 0 and not self.compilation_should_fail:
@@ -263,7 +285,7 @@ class FuncTestFile:
         if len(self.input_output) != 0 and self.compilation_should_fail:
             raise ParseInputError("TESTCASE present, but compilation_should_fail")
 
-    def parse_string_value(self, lines: list[str]) -> list[str]:
+    def parse_string_value(self, lines: list[str], allow_multiline = True) -> list[str]:
         # a tag must be followed by a space (single-line), e.g. '@stderr some text'
         # or be a multi-line value, surrounded by """
         line = lines[self.line_idx]
@@ -274,6 +296,8 @@ class FuncTestFile:
             raise ParseInputError('%s value is empty (not followed by a string or a multiline """)' % line)
         if is_single_line and is_multi_line:
             raise ParseInputError('%s value is both single-line and followed by """' % line[:pos_sp])
+        if is_multi_line and not allow_multiline:
+            raise ParseInputError("%s value should be single-line" % line)
 
         if is_single_line:
             return [line[pos_sp + 1:].strip()]
@@ -312,6 +336,8 @@ class FuncTestFile:
             f.write("\"%s\" include <s constant code\n" % self.get_compiled_fif_filename())
             for t in self.input_output:
                 f.write("%s %d code 1 runvmx abort\"exitcode is not 0\" .s cr { drop } depth 1- times\n" % (t.input, t.method_id))
+            if self.expected_hash is not None:
+                f.write("\"%s\" include hash .s\n" % self.get_compiled_fif_filename())
 
         res = subprocess.run([FIFT_EXECUTABLE, self.get_runner_fif_filename()], capture_output=True, timeout=10)
         exit_code = res.returncode
@@ -319,6 +345,10 @@ class FuncTestFile:
         stdout = str(res.stdout, "utf-8")
         stdout_lines = [x.strip() for x in stdout.split("\n")]
         stdout_lines = [x for x in stdout_lines if x != ""]
+        fif_code_hash = None
+        if self.expected_hash is not None:  # then the last stdout line is a hash
+            fif_code_hash = stdout_lines[-1]
+            stdout_lines = stdout_lines[:-1]
 
         if exit_code != 0:
             raise FiftExecutionFailedError("fift exit_code = %d" % exit_code, stderr)
@@ -335,6 +365,9 @@ class FuncTestFile:
             for fif_codegen in self.fif_codegen:
                 fif_codegen.check(fif_output)
 
+        if self.expected_hash is not None:
+            self.expected_hash.check(fif_code_hash)
+
 
 def run_all_tests(tests: list[str]):
     for ti in range(len(tests)):
@@ -382,6 +415,10 @@ def run_all_tests(tests: list[str]):
             print("  Was compiled to:", testcase.get_compiled_fif_filename(), file=sys.stderr)
             print(open(testcase.get_compiled_fif_filename()).read(), file=sys.stderr)
             exit(2)
+        except CompareCodeHashError as e:
+            print("  Mismatch in code hash:", e, file=sys.stderr)
+            print("  Was compiled to:", testcase.get_compiled_fif_filename(), file=sys.stderr)
+            exit(2)
 
 
 tests = CmdLineOptions(sys.argv).find_tests()
diff --git a/crypto/func/auto-tests/tests/a6.fc b/crypto/func/auto-tests/tests/a6.fc
index 05a49fab..bf36d188 100644
--- a/crypto/func/auto-tests/tests/a6.fc
+++ b/crypto/func/auto-tests/tests/a6.fc
@@ -86,4 +86,6 @@ int main() {
 {-
     method_id | in | out
 TESTCASE | 0  |    | 31415926535897932384626433832795028841971693993751058209749445923078164
+
+@code_hash 84337043972311674339187056298873613816389434478842780265748859098303774481976
 -}
diff --git a/crypto/func/auto-tests/tests/allow_post_modification.fc b/crypto/func/auto-tests/tests/allow_post_modification.fc
index c6082252..bab22fc3 100644
--- a/crypto/func/auto-tests/tests/allow_post_modification.fc
+++ b/crypto/func/auto-tests/tests/allow_post_modification.fc
@@ -61,6 +61,15 @@ global int xx;
   return (xx, xx~inc(xx / 20), xx, xx = xx * 2, xx, xx += 1, xx);
 }
 
+(int, int, int, int, int) test_if_else(int x) method_id(20) {
+  if (x > 10) {
+    return (x~inc(8), x + 1, x = 1, x <<= 3, x);
+  } else {
+    xx = 9;
+    return (x, x~inc(-4), x~inc(-1), x >= 1, x = x + xx);
+  }
+}
+
 () main() {
 }
 
@@ -75,4 +84,8 @@ TESTCASE | 16 | 100 | 100 50 105 210 210 211 211
 TESTCASE | 17 | 100 | 100 50 105 210 210 211 211
 TESTCASE | 18 | 100 | 210 210 211 211 100 50 105
 TESTCASE | 19 | 100 | 100 50 105 210 210 211 211
+TESTCASE | 20 | 80  | 80 89 1 8 8
+TESTCASE | 20 | 9   | 9 -40 -10 -1 13
+
+@code_hash 67078680159561921827850021610104736412668316252257881932102553152922274405210
 -}
diff --git a/crypto/func/auto-tests/tests/asm_arg_order.fc b/crypto/func/auto-tests/tests/asm_arg_order.fc
index b53419e3..84a8a926 100644
--- a/crypto/func/auto-tests/tests/asm_arg_order.fc
+++ b/crypto/func/auto-tests/tests/asm_arg_order.fc
@@ -110,4 +110,6 @@ TESTCASE | 23 |    | [ 11 22 33 ] [ 220 330 110 ]
 TESTCASE | 24 |    | [ 11 22 33 44 55 ] [ 220 330 440 110 550 ]
 TESTCASE | 25 |    | [ 22 33 ] [ 220 330 ]
 TESTCASE | 26 |    | [ 11 22 33 ] [ 220 330 110 ]
+
+@code_hash 53895312198338603934600244087571743055624960603383611438828666636202841531600
 -}
diff --git a/crypto/func/auto-tests/tests/co1.fc b/crypto/func/auto-tests/tests/co1.fc
index 44067243..515c6bc6 100644
--- a/crypto/func/auto-tests/tests/co1.fc
+++ b/crypto/func/auto-tests/tests/co1.fc
@@ -57,4 +57,6 @@ _ main() {
 
 {-
 TESTCASE | 0 | | 0
+
+@code_hash 98157584761932576648981760908342408003231747902562138202913714302941716912743
 -}
diff --git a/crypto/func/auto-tests/tests/s1.fc b/crypto/func/auto-tests/tests/s1.fc
index 1541943d..97b19f16 100644
--- a/crypto/func/auto-tests/tests/s1.fc
+++ b/crypto/func/auto-tests/tests/s1.fc
@@ -51,4 +51,6 @@ _ main() {
 
 {-
 TESTCASE | 0 | | 0
+
+@code_hash 35542701048549611407499491204004197688673151742407097578098250360682143458214
 -}
diff --git a/crypto/func/auto-tests/tests/try-func.fc b/crypto/func/auto-tests/tests/try-func.fc
index 5678965e..fb2a968a 100644
--- a/crypto/func/auto-tests/tests/try-func.fc
+++ b/crypto/func/auto-tests/tests/try-func.fc
@@ -106,4 +106,6 @@ TESTCASE | 4  | 4 8 9 | 4350009
 TESTCASE | 4  | 4 7 9 | 4001009
 TESTCASE | 5  | 4 8 9 | 4350009
 TESTCASE | 5  | 4 7 9 | 4001009
+
+@code_hash 30648920105446086409127767431349650306796188362733360847851465122919640638913
 -}
diff --git a/crypto/func/auto-tests/tests/unbalanced_ret_nested.fc b/crypto/func/auto-tests/tests/unbalanced_ret_nested.fc
index 7ab4bdf0..a54a0dd1 100644
--- a/crypto/func/auto-tests/tests/unbalanced_ret_nested.fc
+++ b/crypto/func/auto-tests/tests/unbalanced_ret_nested.fc
@@ -32,4 +32,6 @@ TESTCASE | 0 | -5 -4 | 111 -70
 TESTCASE | 0 | -4  3 | -7 40
 TESTCASE | 0 | -4 -5 | -7 1110
 TESTCASE | 0 | -4 -4 | -7 -70
+
+@code_hash 68625253347714662162648433047986779710161195298061582217368558479961252943991
 -}
diff --git a/crypto/func/auto-tests/tests/w6.fc b/crypto/func/auto-tests/tests/w6.fc
index 9b91cdf7..44337c12 100644
--- a/crypto/func/auto-tests/tests/w6.fc
+++ b/crypto/func/auto-tests/tests/w6.fc
@@ -14,4 +14,6 @@ int main(int x) {
 {-
     method_id | in | out
 TESTCASE | 0  | 0  | 1
+
+@code_hash 36599880583276393028571473830850694081778552118303309411432666239740650614479
 -}