diff --git a/mypyc/irbuild/format_str_tokenizer.py b/mypyc/irbuild/format_str_tokenizer.py
index 5a35900006d2..1284c99f5c74 100644
--- a/mypyc/irbuild/format_str_tokenizer.py
+++ b/mypyc/irbuild/format_str_tokenizer.py
@@ -23,6 +23,7 @@
     is_str_rprimitive,
 )
 from mypyc.irbuild.builder import IRBuilder
+from mypyc.irbuild.constant_fold import constant_fold_expr
 from mypyc.primitives.bytes_ops import bytes_build_op
 from mypyc.primitives.int_ops import int_to_str_op
 from mypyc.primitives.str_ops import str_build_op, str_op
@@ -143,16 +144,19 @@ def convert_format_expr_to_str(
     for x, format_op in zip(exprs, format_ops):
         node_type = builder.node_type(x)
         if format_op == FormatOp.STR:
-            if is_str_rprimitive(node_type) or isinstance(
-                x, StrExpr
-            ):  # NOTE: why does mypyc think our fake StrExprs are not str rprimitives?
+            if is_str_rprimitive(node_type) or isinstance(x, StrExpr):
+                # NOTE: why does mypyc think our fake StrExprs are not str rprimitives?
                 var_str = builder.accept(x)
+            elif (folded := constant_fold_expr(builder, x)) is not None:
+                var_str = builder.accept(StrExpr(str(folded)))
             elif is_int_rprimitive(node_type) or is_short_int_rprimitive(node_type):
                 var_str = builder.primitive_op(int_to_str_op, [builder.accept(x)], line)
             else:
                 var_str = builder.primitive_op(str_op, [builder.accept(x)], line)
         elif format_op == FormatOp.INT:
-            if is_int_rprimitive(node_type) or is_short_int_rprimitive(node_type):
+            if isinstance(folded := constant_fold_expr(builder, x), int):
+                var_str = builder.accept(StrExpr(str(folded)))
+            elif is_int_rprimitive(node_type) or is_short_int_rprimitive(node_type):
                 var_str = builder.primitive_op(int_to_str_op, [builder.accept(x)], line)
             else:
                 return None
diff --git a/mypyc/test-data/irbuild-str.test b/mypyc/test-data/irbuild-str.test
index 056f120c7bac..471c81cc666f 100644
--- a/mypyc/test-data/irbuild-str.test
+++ b/mypyc/test-data/irbuild-str.test
@@ -638,11 +638,11 @@ floating: Final = 3.14
 boolean: Final = True
 
 def test(x: str) -> str:
-    return f"{string}{integer}{floating}{boolean}{x}{boolean}{floating}{integer}{string}{x}{string}{integer}{floating}{boolean}"
+    return f"{string[:3]}{integer}{floating}{boolean}{x}{boolean}{floating}{integer}{string}{x}{string}{integer}{floating}{boolean}"
 def test2(x: str) -> str:
-    return f"{string}{integer}{floating}{boolean}{x}{boolean}{floating}{integer}{string}{x}{string}{integer}{floating}{boolean}{x}"
+    return f"{string[-3:]}{integer}{floating}{boolean}{x}{boolean}{floating}{integer}{string}{x}{string}{integer}{floating}{boolean}{x}"
 def test3(x: str) -> str:
-    return f"{x}{string}{integer}{floating}{boolean}{x}{boolean}{floating}{integer}{string}{x}{string}{integer}{floating}{boolean}{x}"
+    return f"{x}{string[:]}{integer}{floating}{boolean}{x}{boolean}{floating}{integer}{string}{x}{string}{integer}{floating}{boolean}{x}"
 
 [out]
 def test(x):