diff --git a/crates/ruff_linter/resources/test/fixtures/flake8_bandit/S604.py b/crates/ruff_linter/resources/test/fixtures/flake8_bandit/S604.py
index 49d906508b..3ee5edd1f1 100644
--- a/crates/ruff_linter/resources/test/fixtures/flake8_bandit/S604.py
+++ b/crates/ruff_linter/resources/test/fixtures/flake8_bandit/S604.py
@@ -22,3 +22,15 @@ foo(shell=lambda: 0)
 foo(shell=f"{b''}")
 x = 1
 foo(shell=f"{x=}")
+print(bool(dict(shell=f"{f""!s}")["shell"]))
+
+# Unknown truthiness
+print(bool(dict(shell=f"{"x":.0}")["shell"]))
+
+
+class C:
+    def __gt__(self, other):
+        return ""
+
+
+print(bool(dict(shell=f"{C() > C()}")["shell"]))
diff --git a/crates/ruff_linter/src/rules/flake8_bandit/snapshots/ruff_linter__rules__flake8_bandit__tests__S604_S604.py.snap b/crates/ruff_linter/src/rules/flake8_bandit/snapshots/ruff_linter__rules__flake8_bandit__tests__S604_S604.py.snap
index 798e916ba6..569e4819fc 100644
--- a/crates/ruff_linter/src/rules/flake8_bandit/snapshots/ruff_linter__rules__flake8_bandit__tests__S604_S604.py.snap
+++ b/crates/ruff_linter/src/rules/flake8_bandit/snapshots/ruff_linter__rules__flake8_bandit__tests__S604_S604.py.snap
@@ -90,4 +90,5 @@ S604 Function call with truthy `shell` parameter identified, security issue
 23 | x = 1
 24 | foo(shell=f"{x=}")
    | ^^^
+25 | print(bool(dict(shell=f"{f""!s}")["shell"]))
    |
diff --git a/crates/ruff_python_ast/src/helpers.rs b/crates/ruff_python_ast/src/helpers.rs
index 9680d03ec3..8c604c4ed2 100644
--- a/crates/ruff_python_ast/src/helpers.rs
+++ b/crates/ruff_python_ast/src/helpers.rs
@@ -1376,7 +1376,9 @@ fn is_non_empty_f_string(expr: &ast::ExprFString) -> bool {
             Expr::ListComp(_) => true,
             Expr::SetComp(_) => true,
             Expr::DictComp(_) => true,
-            Expr::Compare(_) => true,
+            // Compare can return any value, even empty string
+            // https://docs.python.org/3/reference/datamodel.html#object.__ge__
+            Expr::Compare(_) => false,
             Expr::NumberLiteral(_) => true,
             Expr::BooleanLiteral(_) => true,
             Expr::NoneLiteral(_) => true,
@@ -1418,12 +1420,16 @@ fn is_non_empty_f_string(expr: &ast::ExprFString) -> bool {
     expr.value.iter().any(|part| match part {
         ast::FStringPart::Literal(string_literal) => !string_literal.is_empty(),
         ast::FStringPart::FString(f_string) => {
-            f_string.elements.iter().all(|element| match element {
-                InterpolatedStringElement::Literal(string_literal) => !string_literal.is_empty(),
-                InterpolatedStringElement::Interpolation(f_string) => {
-                    f_string.debug_text.is_some() || inner(&f_string.expression)
-                }
-            })
+            !f_string.elements.is_empty()
+                && f_string.elements.iter().all(|element| match element {
+                    InterpolatedStringElement::Literal(string_literal) => {
+                        !string_literal.is_empty()
+                    }
+                    InterpolatedStringElement::Interpolation(f_string) => {
+                        f_string.format_spec.is_none()
+                            && (f_string.debug_text.is_some() || inner(&f_string.expression))
+                    }
+                })
         }
     })
 }