diff --git a/lib/fizzy/execute.cpp b/lib/fizzy/execute.cpp
index 8303f0ddf..828bd31e3 100644
--- a/lib/fizzy/execute.cpp
+++ b/lib/fizzy/execute.cpp
@@ -596,7 +596,8 @@ std::unique_ptr<Instance> instantiate(Module module,
     return instance;
 }
 
-ExecutionResult execute(Instance& instance, FuncIdx func_idx, span<const uint64_t> args, int depth)
+ExecutionResult execute(
+    Instance& instance, FuncIdx func_idx, span<const uint64_t> args, int depth) noexcept
 {
     assert(depth >= 0);
     if (depth > CallStackLimit)
@@ -1448,7 +1449,7 @@ ExecutionResult execute(Instance& instance, FuncIdx func_idx, span<const uint64_
         case Instr::i64_reinterpret_f64:
         case Instr::f32_reinterpret_i32:
         case Instr::f64_reinterpret_i64:
-//            throw unsupported_feature("Floating point instruction.");
+            //            throw unsupported_feature("Floating point instruction.");
         default:
             assert(false);
             break;
diff --git a/lib/fizzy/execute.hpp b/lib/fizzy/execute.hpp
index c35a2ec10..e64acf770 100644
--- a/lib/fizzy/execute.hpp
+++ b/lib/fizzy/execute.hpp
@@ -104,10 +104,10 @@ std::unique_ptr<Instance> instantiate(Module module,
 
 // Execute a function on an instance.
 ExecutionResult execute(
-    Instance& instance, FuncIdx func_idx, span<const uint64_t> args, int depth = 0);
+    Instance& instance, FuncIdx func_idx, span<const uint64_t> args, int depth = 0) noexcept;
 
 inline ExecutionResult execute(
-    Instance& instance, FuncIdx func_idx, std::initializer_list<uint64_t> args)
+    Instance& instance, FuncIdx func_idx, std::initializer_list<uint64_t> args) noexcept
 {
     return execute(instance, func_idx, span<const uint64_t>{args});
 }