diff --git a/Include/internal/pycore_optimizer.h b/Include/internal/pycore_optimizer.h
index 265eae4e290..614850468ec 100644
--- a/Include/internal/pycore_optimizer.h
+++ b/Include/internal/pycore_optimizer.h
@@ -95,6 +95,8 @@ extern void _Py_uop_sym_set_null(_Py_UopsSymbol *sym);
 extern void _Py_uop_sym_set_non_null(_Py_UopsSymbol *sym);
 extern void _Py_uop_sym_set_type(_Py_UopsSymbol *sym, PyTypeObject *typ);
 extern void _Py_uop_sym_set_const(_Py_UopsSymbol *sym, PyObject *const_val);
+extern bool _Py_uop_sym_is_bottom(_Py_UopsSymbol *sym);
+
 
 extern int _Py_uop_abstractcontext_init(_Py_UOpsContext *ctx);
 extern void _Py_uop_abstractcontext_fini(_Py_UOpsContext *ctx);
diff --git a/Lib/test/test_capi/test_opt.py b/Lib/test/test_capi/test_opt.py
index 25fc36dec93..e1aef21b2c7 100644
--- a/Lib/test/test_capi/test_opt.py
+++ b/Lib/test/test_capi/test_opt.py
@@ -210,6 +210,8 @@ class TestExecutorInvalidation(unittest.TestCase):
         exe = get_first_executor(f)
         self.assertIsNone(exe)
 
+
+@unittest.skipIf(os.getenv("PYTHON_UOPS_OPTIMIZE") == "0", "Needs uop optimizer to run.")
 class TestUops(unittest.TestCase):
 
     def test_basic_loop(self):
@@ -570,7 +572,7 @@ class TestUops(unittest.TestCase):
         self.assertLessEqual(count, 2)
 
 
-@unittest.skipIf(os.getenv("PYTHONUOPSOPTIMIZE", default=0) == 0, "Needs uop optimizer to run.")
+@unittest.skipIf(os.getenv("PYTHON_UOPS_OPTIMIZE") == "0", "Needs uop optimizer to run.")
 class TestUopsOptimization(unittest.TestCase):
 
     def _run_with_optimizer(self, testfunc, arg):
@@ -890,5 +892,22 @@ class TestUopsOptimization(unittest.TestCase):
         self.assertLessEqual(len(guard_both_float_count), 1)
         self.assertIn("_COMPARE_OP_STR", uops)
 
+    def test_type_inconsistency(self):
+        def testfunc(n):
+            for i in range(n):
+                x = _test_global + _test_global
+        # Must be a real global else it won't be optimized to _LOAD_CONST_INLINE
+        global _test_global
+        _test_global = 0
+        _, ex = self._run_with_optimizer(testfunc, 16)
+        self.assertIsNone(ex)
+        _test_global = 1.2
+        _, ex = self._run_with_optimizer(testfunc, 16)
+        self.assertIsNotNone(ex)
+        uops = get_opnames(ex)
+        self.assertIn("_GUARD_BOTH_INT", uops)
+        self.assertIn("_BINARY_OP_ADD_INT", uops)
+
+
 if __name__ == "__main__":
     unittest.main()
diff --git a/Python/optimizer.c b/Python/optimizer.c
index c04ee17ee21..acd6d52c4a8 100644
--- a/Python/optimizer.c
+++ b/Python/optimizer.c
@@ -1008,8 +1008,8 @@ uop_optimize(
         return err;
     }
     OPT_STAT_INC(traces_created);
-    char *uop_optimize = Py_GETENV("PYTHONUOPSOPTIMIZE");
-    if (uop_optimize == NULL || *uop_optimize > '0') {
+    char *env_var = Py_GETENV("PYTHON_UOPS_OPTIMIZE");
+    if (env_var == NULL || *env_var == '\0' || *env_var > '0') {
         err = _Py_uop_analyze_and_optimize(frame, buffer,
                                            UOP_MAX_TRACE_LENGTH,
                                            curr_stackentries, &dependencies);
diff --git a/Python/optimizer_analysis.c b/Python/optimizer_analysis.c
index 8e408ffbb1c..2a7ef4ec919 100644
--- a/Python/optimizer_analysis.c
+++ b/Python/optimizer_analysis.c
@@ -297,6 +297,7 @@ remove_globals(_PyInterpreterFrame *frame, _PyUOpInstruction *buffer,
 #define sym_set_non_null _Py_uop_sym_set_non_null
 #define sym_set_type _Py_uop_sym_set_type
 #define sym_set_const _Py_uop_sym_set_const
+#define sym_is_bottom _Py_uop_sym_is_bottom
 #define frame_new _Py_uop_frame_new
 #define frame_pop _Py_uop_frame_pop
 
@@ -510,12 +511,9 @@ _Py_uop_analyze_and_optimize(
 
     peephole_opt(frame, buffer, buffer_size);
 
-    char *uop_optimize = Py_GETENV("PYTHONUOPSOPTIMIZE");
-    if (uop_optimize != NULL && *uop_optimize > '0') {
-        err = optimize_uops(
-            (PyCodeObject *)frame->f_executable, buffer,
-            buffer_size, curr_stacklen, dependencies);
-    }
+    err = optimize_uops(
+        (PyCodeObject *)frame->f_executable, buffer,
+        buffer_size, curr_stacklen, dependencies);
 
     if (err == 0) {
         goto not_ready;
diff --git a/Python/optimizer_bytecodes.c b/Python/optimizer_bytecodes.c
index b65e90bf980..928c22da16b 100644
--- a/Python/optimizer_bytecodes.c
+++ b/Python/optimizer_bytecodes.c
@@ -25,6 +25,7 @@ typedef struct _Py_UOpsAbstractFrame _Py_UOpsAbstractFrame;
 #define sym_set_non_null _Py_uop_sym_set_non_null
 #define sym_set_type _Py_uop_sym_set_type
 #define sym_set_const _Py_uop_sym_set_const
+#define sym_is_bottom _Py_uop_sym_is_bottom
 #define frame_new _Py_uop_frame_new
 #define frame_pop _Py_uop_frame_pop
 
@@ -107,7 +108,9 @@ dummy_func(void) {
     }
 
     op(_BINARY_OP_ADD_INT, (left, right -- res)) {
-        if (sym_is_const(left) && sym_is_const(right)) {
+        if (sym_is_const(left) && sym_is_const(right) &&
+            sym_matches_type(left, &PyLong_Type) && sym_matches_type(right, &PyLong_Type))
+        {
             assert(PyLong_CheckExact(sym_get_const(left)));
             assert(PyLong_CheckExact(sym_get_const(right)));
             PyObject *temp = _PyLong_Add((PyLongObject *)sym_get_const(left),
@@ -115,7 +118,9 @@ dummy_func(void) {
             if (temp == NULL) {
                 goto error;
             }
-            OUT_OF_SPACE_IF_NULL(res = sym_new_const(ctx, temp));
+            res = sym_new_const(ctx, temp);
+            Py_DECREF(temp);
+            OUT_OF_SPACE_IF_NULL(res);
             // TODO gh-115506:
             // replace opcode with constant propagated one and add tests!
         }
@@ -125,7 +130,9 @@ dummy_func(void) {
     }
 
     op(_BINARY_OP_SUBTRACT_INT, (left, right -- res)) {
-        if (sym_is_const(left) && sym_is_const(right)) {
+        if (sym_is_const(left) && sym_is_const(right) &&
+            sym_matches_type(left, &PyLong_Type) && sym_matches_type(right, &PyLong_Type))
+        {
             assert(PyLong_CheckExact(sym_get_const(left)));
             assert(PyLong_CheckExact(sym_get_const(right)));
             PyObject *temp = _PyLong_Subtract((PyLongObject *)sym_get_const(left),
@@ -133,7 +140,9 @@ dummy_func(void) {
             if (temp == NULL) {
                 goto error;
             }
-            OUT_OF_SPACE_IF_NULL(res = sym_new_const(ctx, temp));
+            res = sym_new_const(ctx, temp);
+            Py_DECREF(temp);
+            OUT_OF_SPACE_IF_NULL(res);
             // TODO gh-115506:
             // replace opcode with constant propagated one and add tests!
         }
@@ -143,7 +152,9 @@ dummy_func(void) {
     }
 
     op(_BINARY_OP_MULTIPLY_INT, (left, right -- res)) {
-        if (sym_is_const(left) && sym_is_const(right)) {
+        if (sym_is_const(left) && sym_is_const(right) &&
+            sym_matches_type(left, &PyLong_Type) && sym_matches_type(right, &PyLong_Type))
+        {
             assert(PyLong_CheckExact(sym_get_const(left)));
             assert(PyLong_CheckExact(sym_get_const(right)));
             PyObject *temp = _PyLong_Multiply((PyLongObject *)sym_get_const(left),
@@ -151,7 +162,9 @@ dummy_func(void) {
             if (temp == NULL) {
                 goto error;
             }
-            OUT_OF_SPACE_IF_NULL(res = sym_new_const(ctx, temp));
+            res = sym_new_const(ctx, temp);
+            Py_DECREF(temp);
+            OUT_OF_SPACE_IF_NULL(res);
             // TODO gh-115506:
             // replace opcode with constant propagated one and add tests!
         }
@@ -161,7 +174,9 @@ dummy_func(void) {
     }
 
     op(_BINARY_OP_ADD_FLOAT, (left, right -- res)) {
-        if (sym_is_const(left) && sym_is_const(right)) {
+        if (sym_is_const(left) && sym_is_const(right) &&
+            sym_matches_type(left, &PyFloat_Type) && sym_matches_type(right, &PyFloat_Type))
+        {
             assert(PyFloat_CheckExact(sym_get_const(left)));
             assert(PyFloat_CheckExact(sym_get_const(right)));
             PyObject *temp = PyFloat_FromDouble(
@@ -171,6 +186,8 @@ dummy_func(void) {
                 goto error;
             }
             res = sym_new_const(ctx, temp);
+            Py_DECREF(temp);
+            OUT_OF_SPACE_IF_NULL(res);
             // TODO gh-115506:
             // replace opcode with constant propagated one and update tests!
         }
@@ -180,7 +197,9 @@ dummy_func(void) {
     }
 
     op(_BINARY_OP_SUBTRACT_FLOAT, (left, right -- res)) {
-        if (sym_is_const(left) && sym_is_const(right)) {
+        if (sym_is_const(left) && sym_is_const(right) &&
+            sym_matches_type(left, &PyFloat_Type) && sym_matches_type(right, &PyFloat_Type))
+        {
             assert(PyFloat_CheckExact(sym_get_const(left)));
             assert(PyFloat_CheckExact(sym_get_const(right)));
             PyObject *temp = PyFloat_FromDouble(
@@ -190,6 +209,8 @@ dummy_func(void) {
                 goto error;
             }
             res = sym_new_const(ctx, temp);
+            Py_DECREF(temp);
+            OUT_OF_SPACE_IF_NULL(res);
             // TODO gh-115506:
             // replace opcode with constant propagated one and update tests!
         }
@@ -199,7 +220,9 @@ dummy_func(void) {
     }
 
     op(_BINARY_OP_MULTIPLY_FLOAT, (left, right -- res)) {
-        if (sym_is_const(left) && sym_is_const(right)) {
+        if (sym_is_const(left) && sym_is_const(right) &&
+            sym_matches_type(left, &PyFloat_Type) && sym_matches_type(right, &PyFloat_Type))
+        {
             assert(PyFloat_CheckExact(sym_get_const(left)));
             assert(PyFloat_CheckExact(sym_get_const(right)));
             PyObject *temp = PyFloat_FromDouble(
@@ -209,6 +232,8 @@ dummy_func(void) {
                 goto error;
             }
             res = sym_new_const(ctx, temp);
+            Py_DECREF(temp);
+            OUT_OF_SPACE_IF_NULL(res);
             // TODO gh-115506:
             // replace opcode with constant propagated one and update tests!
         }
diff --git a/Python/optimizer_cases.c.h b/Python/optimizer_cases.c.h
index 9e99c8395a4..9b387c07850 100644
--- a/Python/optimizer_cases.c.h
+++ b/Python/optimizer_cases.c.h
@@ -183,7 +183,9 @@
             _Py_UopsSymbol *res;
             right = stack_pointer[-1];
             left = stack_pointer[-2];
-            if (sym_is_const(left) && sym_is_const(right)) {
+            if (sym_is_const(left) && sym_is_const(right) &&
+                sym_matches_type(left, &PyLong_Type) && sym_matches_type(right, &PyLong_Type))
+            {
                 assert(PyLong_CheckExact(sym_get_const(left)));
                 assert(PyLong_CheckExact(sym_get_const(right)));
                 PyObject *temp = _PyLong_Multiply((PyLongObject *)sym_get_const(left),
@@ -191,7 +193,9 @@
                 if (temp == NULL) {
                     goto error;
                 }
-                OUT_OF_SPACE_IF_NULL(res = sym_new_const(ctx, temp));
+                res = sym_new_const(ctx, temp);
+                Py_DECREF(temp);
+                OUT_OF_SPACE_IF_NULL(res);
                 // TODO gh-115506:
                 // replace opcode with constant propagated one and add tests!
             }
@@ -209,7 +213,9 @@
             _Py_UopsSymbol *res;
             right = stack_pointer[-1];
             left = stack_pointer[-2];
-            if (sym_is_const(left) && sym_is_const(right)) {
+            if (sym_is_const(left) && sym_is_const(right) &&
+                sym_matches_type(left, &PyLong_Type) && sym_matches_type(right, &PyLong_Type))
+            {
                 assert(PyLong_CheckExact(sym_get_const(left)));
                 assert(PyLong_CheckExact(sym_get_const(right)));
                 PyObject *temp = _PyLong_Add((PyLongObject *)sym_get_const(left),
@@ -217,7 +223,9 @@
                 if (temp == NULL) {
                     goto error;
                 }
-                OUT_OF_SPACE_IF_NULL(res = sym_new_const(ctx, temp));
+                res = sym_new_const(ctx, temp);
+                Py_DECREF(temp);
+                OUT_OF_SPACE_IF_NULL(res);
                 // TODO gh-115506:
                 // replace opcode with constant propagated one and add tests!
             }
@@ -235,7 +243,9 @@
             _Py_UopsSymbol *res;
             right = stack_pointer[-1];
             left = stack_pointer[-2];
-            if (sym_is_const(left) && sym_is_const(right)) {
+            if (sym_is_const(left) && sym_is_const(right) &&
+                sym_matches_type(left, &PyLong_Type) && sym_matches_type(right, &PyLong_Type))
+            {
                 assert(PyLong_CheckExact(sym_get_const(left)));
                 assert(PyLong_CheckExact(sym_get_const(right)));
                 PyObject *temp = _PyLong_Subtract((PyLongObject *)sym_get_const(left),
@@ -243,7 +253,9 @@
                 if (temp == NULL) {
                     goto error;
                 }
-                OUT_OF_SPACE_IF_NULL(res = sym_new_const(ctx, temp));
+                res = sym_new_const(ctx, temp);
+                Py_DECREF(temp);
+                OUT_OF_SPACE_IF_NULL(res);
                 // TODO gh-115506:
                 // replace opcode with constant propagated one and add tests!
             }
@@ -275,7 +287,9 @@
             _Py_UopsSymbol *res;
             right = stack_pointer[-1];
             left = stack_pointer[-2];
-            if (sym_is_const(left) && sym_is_const(right)) {
+            if (sym_is_const(left) && sym_is_const(right) &&
+                sym_matches_type(left, &PyFloat_Type) && sym_matches_type(right, &PyFloat_Type))
+            {
                 assert(PyFloat_CheckExact(sym_get_const(left)));
                 assert(PyFloat_CheckExact(sym_get_const(right)));
                 PyObject *temp = PyFloat_FromDouble(
@@ -285,6 +299,8 @@
                     goto error;
                 }
                 res = sym_new_const(ctx, temp);
+                Py_DECREF(temp);
+                OUT_OF_SPACE_IF_NULL(res);
                 // TODO gh-115506:
                 // replace opcode with constant propagated one and update tests!
             }
@@ -302,7 +318,9 @@
             _Py_UopsSymbol *res;
             right = stack_pointer[-1];
             left = stack_pointer[-2];
-            if (sym_is_const(left) && sym_is_const(right)) {
+            if (sym_is_const(left) && sym_is_const(right) &&
+                sym_matches_type(left, &PyFloat_Type) && sym_matches_type(right, &PyFloat_Type))
+            {
                 assert(PyFloat_CheckExact(sym_get_const(left)));
                 assert(PyFloat_CheckExact(sym_get_const(right)));
                 PyObject *temp = PyFloat_FromDouble(
@@ -312,6 +330,8 @@
                     goto error;
                 }
                 res = sym_new_const(ctx, temp);
+                Py_DECREF(temp);
+                OUT_OF_SPACE_IF_NULL(res);
                 // TODO gh-115506:
                 // replace opcode with constant propagated one and update tests!
             }
@@ -329,7 +349,9 @@
             _Py_UopsSymbol *res;
             right = stack_pointer[-1];
             left = stack_pointer[-2];
-            if (sym_is_const(left) && sym_is_const(right)) {
+            if (sym_is_const(left) && sym_is_const(right) &&
+                sym_matches_type(left, &PyFloat_Type) && sym_matches_type(right, &PyFloat_Type))
+            {
                 assert(PyFloat_CheckExact(sym_get_const(left)));
                 assert(PyFloat_CheckExact(sym_get_const(right)));
                 PyObject *temp = PyFloat_FromDouble(
@@ -339,6 +361,8 @@
                     goto error;
                 }
                 res = sym_new_const(ctx, temp);
+                Py_DECREF(temp);
+                OUT_OF_SPACE_IF_NULL(res);
                 // TODO gh-115506:
                 // replace opcode with constant propagated one and update tests!
             }
diff --git a/Python/optimizer_symbols.c b/Python/optimizer_symbols.c
index 158ee67d19f..a529cc2f5cf 100644
--- a/Python/optimizer_symbols.c
+++ b/Python/optimizer_symbols.c
@@ -77,7 +77,7 @@ sym_set_bottom(_Py_UopsSymbol *sym)
     Py_CLEAR(sym->const_val);
 }
 
-static inline bool
+bool
 _Py_uop_sym_is_bottom(_Py_UopsSymbol *sym)
 {
     if ((sym->flags & IS_NULL) && (sym->flags & NOT_NULL)) {