diff --git a/tests/cases/corner_cases.cddl b/tests/cases/corner_cases.cddl
index fe520d7b..1d5ef5e0 100644
--- a/tests/cases/corner_cases.cddl
+++ b/tests/cases/corner_cases.cddl
@@ -254,3 +254,8 @@ Uint64List = [
 	? uint64_lit: 0x0123456789abcdef,
 	* nint64_lit: -0x0123456789abcdef,
 ]
+
+BstrSize = {
+    bstr12,
+}
+bstr12 = ("s" : bstr .size 12)
diff --git a/tests/decode/test5_corner_cases/CMakeLists.txt b/tests/decode/test5_corner_cases/CMakeLists.txt
index f353edd9..18a586aa 100644
--- a/tests/decode/test5_corner_cases/CMakeLists.txt
+++ b/tests/decode/test5_corner_cases/CMakeLists.txt
@@ -53,6 +53,7 @@ set(py_command
     Intmax2
     InvalidIdentifiers
     Uint64List
+    BstrSize
   --decode
   --git-sha-header
   --short-names
diff --git a/tests/decode/test5_corner_cases/src/main.c b/tests/decode/test5_corner_cases/src/main.c
index a7090322..77dfa955 100644
--- a/tests/decode/test5_corner_cases/src/main.c
+++ b/tests/decode/test5_corner_cases/src/main.c
@@ -2103,4 +2103,24 @@ ZTEST(cbor_decode_test5, test_uint64_list)
 }
 
 
+ZTEST(cbor_decode_test5, test_bstr_size)
+{
+	uint8_t bstr_size_payload1[] = {MAP(1),
+		0x61, 's',
+		0x4c, 0x00, 0x11, 0x22, 0x33, 0x44, 0x55,
+		0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb,
+		END
+	};
+
+	struct BstrSize result;
+	size_t num_decode;
+
+	zassert_equal(ZCBOR_SUCCESS, cbor_decode_BstrSize(bstr_size_payload1,
+		sizeof(bstr_size_payload1), &result, &num_decode), NULL);
+	zassert_equal(sizeof(bstr_size_payload1), num_decode, NULL);
+
+	zassert_equal(12, result.bstr12_m.s.len, NULL);
+}
+
+
 ZTEST_SUITE(cbor_decode_test5, NULL, NULL, NULL, NULL, NULL);
diff --git a/zcbor/zcbor.py b/zcbor/zcbor.py
index f227434c..9f810f8a 100755
--- a/zcbor/zcbor.py
+++ b/zcbor/zcbor.py
@@ -2389,7 +2389,8 @@ def range_checks(self, access):
             if self.max_size is not None:
                 range_checks.append(f"({access}.len <= {self.max_size})")
         elif self.type == "OTHER":
-            range_checks.extend(self.my_types[self.value].range_checks(access))
+            if not self.my_types[self.value].single_func_impl_condition():
+                range_checks.extend(self.my_types[self.value].range_checks(access))
 
         if range_checks:
             range_checks[0] = "((" + range_checks[0]