diff --git a/src/interpreter/func.rs b/src/interpreter/func.rs
new file mode 100644
index 0000000..1b098d8
--- /dev/null
+++ b/src/interpreter/func.rs
@@ -0,0 +1,106 @@
+use std::rc::Rc;
+use std::fmt;
+use std::collections::HashMap;
+use std::any::Any;
+use elements::{FunctionType, Opcodes, Local};
+use interpreter::{Error, ModuleInstance};
+use interpreter::runner::{prepare_function_args, FunctionContext, Interpreter};
+use interpreter::host::AnyFunc;
+use interpreter::value::RuntimeValue;
+use common::stack::StackWithLimit;
+use common::{DEFAULT_FRAME_STACK_LIMIT, DEFAULT_VALUE_STACK_LIMIT};
+
+#[derive(Clone)]
+pub enum FuncInstance {
+	Internal {
+		func_type: Rc<FunctionType>,
+		module: Rc<ModuleInstance>,
+		body: Rc<FuncBody>,
+	},
+	Host {
+		func_type: Rc<FunctionType>,
+		host_func: Rc<AnyFunc>,
+	},
+}
+
+impl fmt::Debug for FuncInstance {
+	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+		match self {
+			&FuncInstance::Internal {
+				ref func_type,
+				ref module,
+				..
+			} => write!(
+				f,
+				"Internal {{ type={:?}, module={:?} }}",
+				func_type,
+				module
+			),
+			&FuncInstance::Host { ref func_type, .. } => {
+				write!(f, "Host {{ type={:?} }}", func_type)
+			}
+		}
+	}
+}
+
+impl FuncInstance {
+	pub fn func_type(&self) -> Rc<FunctionType> {
+		match *self {
+			FuncInstance::Internal { ref func_type, .. } |
+			FuncInstance::Host { ref func_type, .. } => Rc::clone(func_type),
+		}
+	}
+
+	pub fn body(&self) -> Option<Rc<FuncBody>> {
+		match *self {
+			FuncInstance::Internal { ref body, .. } => Some(Rc::clone(body)),
+			FuncInstance::Host { .. } => None,
+		}
+	}
+}
+
+impl FuncInstance {
+	pub fn invoke<St: 'static>(
+		func: Rc<FuncInstance>,
+		args: Vec<RuntimeValue>,
+		state: &mut St,
+	) -> Result<Option<RuntimeValue>, Error> {
+		enum InvokeKind {
+			Internal(FunctionContext),
+			Host(Rc<AnyFunc>, Vec<RuntimeValue>),
+		}
+
+		let result = match *func {
+			FuncInstance::Internal { ref func_type, .. } => {
+				let mut args = StackWithLimit::with_data(args, DEFAULT_VALUE_STACK_LIMIT);
+				let args = prepare_function_args(func_type, &mut args)?;
+				let context = FunctionContext::new(
+					Rc::clone(&func),
+					DEFAULT_VALUE_STACK_LIMIT,
+					DEFAULT_FRAME_STACK_LIMIT,
+					func_type,
+					args,
+				);
+				InvokeKind::Internal(context)
+			}
+			FuncInstance::Host { ref host_func, .. } => {
+				InvokeKind::Host(Rc::clone(host_func), args)
+			}
+		};
+
+		match result {
+			InvokeKind::Internal(ctx) => {
+				let mut interpreter = Interpreter::new(state);
+				interpreter.run_function(ctx)
+			}
+			InvokeKind::Host(host_func, args) => host_func.call_as_any(state as &mut Any, &args),
+		}
+	}
+}
+
+#[derive(Clone, Debug)]
+pub struct FuncBody {
+	pub locals: Vec<Local>,
+	pub opcodes: Opcodes,
+	pub labels: HashMap<usize, usize>,
+}
diff --git a/src/interpreter/host.rs b/src/interpreter/host.rs
index 0c1add7..49539fc 100644
--- a/src/interpreter/host.rs
+++ b/src/interpreter/host.rs
@@ -3,7 +3,8 @@ use std::rc::Rc;
 use std::marker::PhantomData;
 use std::collections::HashMap;
 use elements::{FunctionType, ValueType, GlobalType, MemoryType, TableType};
-use interpreter::store::{ExternVal, ModuleInstance, FuncInstance};
+use interpreter::store::{ExternVal, ModuleInstance};
+use interpreter::func::FuncInstance;
 use interpreter::global::GlobalInstance;
 use interpreter::memory::MemoryInstance;
 use interpreter::table::TableInstance;
diff --git a/src/interpreter/imports.rs b/src/interpreter/imports.rs
index 70e3c1d..1f94688 100644
--- a/src/interpreter/imports.rs
+++ b/src/interpreter/imports.rs
@@ -1,7 +1,7 @@
 use std::rc::Rc;
 use std::collections::HashMap;
 use elements::{FunctionType, GlobalType, MemoryType, TableType};
-use interpreter::store::FuncInstance;
+use interpreter::func::FuncInstance;
 use interpreter::global::GlobalInstance;
 use interpreter::memory::MemoryInstance;
 use interpreter::table::TableInstance;
diff --git a/src/interpreter/mod.rs b/src/interpreter/mod.rs
index ffafe4b..00f528f 100644
--- a/src/interpreter/mod.rs
+++ b/src/interpreter/mod.rs
@@ -141,6 +141,7 @@ mod store;
 mod host;
 mod imports;
 mod global;
+mod func;
 
 #[cfg(test)]
 mod tests;
@@ -152,5 +153,6 @@ pub use self::program::ProgramInstance;
 pub use self::value::RuntimeValue;
 pub use self::host::{HostModule, HostModuleBuilder, Func1, AnyFunc, AsReturnVal, FromArg};
 pub use self::imports::{ImportResolver, Imports};
-pub use self::store::{FuncInstance, ModuleInstance};
+pub use self::store::{ModuleInstance};
 pub use self::global::GlobalInstance;
+pub use self::func::FuncInstance;
diff --git a/src/interpreter/program.rs b/src/interpreter/program.rs
index 9d37104..7e46aec 100644
--- a/src/interpreter/program.rs
+++ b/src/interpreter/program.rs
@@ -2,7 +2,8 @@ use std::rc::Rc;
 use std::collections::HashMap;
 use elements::Module;
 use interpreter::Error;
-use interpreter::store::{FuncInstance, ModuleInstance};
+use interpreter::store::{ModuleInstance};
+use interpreter::func::FuncInstance;
 use interpreter::host::HostModule;
 use interpreter::value::RuntimeValue;
 use interpreter::imports::{Imports, ImportResolver};
diff --git a/src/interpreter/runner.rs b/src/interpreter/runner.rs
index 77552b1..4c13908 100644
--- a/src/interpreter/runner.rs
+++ b/src/interpreter/runner.rs
@@ -7,7 +7,8 @@ use std::iter::repeat;
 use std::collections::{HashMap, VecDeque};
 use elements::{Opcode, BlockType, Local, FunctionType};
 use interpreter::Error;
-use interpreter::store::{FuncInstance, ModuleInstance};
+use interpreter::store::ModuleInstance;
+use interpreter::func::FuncInstance;
 use interpreter::value::{
 	RuntimeValue, TryInto, WrapInto, TryTruncateInto, ExtendInto,
 	ArithmeticOps, Integer, Float, LittleEndianConvert, TransmuteInto,
diff --git a/src/interpreter/store.rs b/src/interpreter/store.rs
index 931d3e2..fa3d26d 100644
--- a/src/interpreter/store.rs
+++ b/src/interpreter/store.rs
@@ -1,19 +1,14 @@
 use std::rc::Rc;
 use std::cell::RefCell;
-use std::any::Any;
-use std::fmt;
 use std::collections::HashMap;
-use elements::{External, FunctionType, GlobalType, InitExpr, Internal, Local, MemoryType, Module,
-               Opcode, Opcodes, ResizableLimits, TableType, Type};
+use elements::{External, FunctionType, GlobalType, InitExpr, Internal, MemoryType, Module,
+               Opcode, ResizableLimits, TableType, Type};
 use interpreter::{Error, MemoryInstance, RuntimeValue, TableInstance};
-use interpreter::runner::{prepare_function_args, FunctionContext, Interpreter};
-use interpreter::host::AnyFunc;
 use interpreter::imports::{ImportResolver, Imports};
 use interpreter::global::GlobalInstance;
+use interpreter::func::{FuncInstance, FuncBody};
 use validation::validate_module;
-use common::{DEFAULT_FRAME_STACK_LIMIT, DEFAULT_MEMORY_INDEX, DEFAULT_TABLE_INDEX,
-             DEFAULT_VALUE_STACK_LIMIT};
-use common::stack::StackWithLimit;
+use common::{DEFAULT_MEMORY_INDEX, DEFAULT_TABLE_INDEX};
 
 #[derive(Clone, Debug)]
 pub enum ExternVal {
@@ -53,101 +48,6 @@ impl ExternVal {
 	}
 }
 
-#[derive(Clone)]
-pub enum FuncInstance {
-	Internal {
-		func_type: Rc<FunctionType>,
-		module: Rc<ModuleInstance>,
-		body: Rc<FuncBody>,
-	},
-	Host {
-		func_type: Rc<FunctionType>,
-		host_func: Rc<AnyFunc>,
-	},
-}
-
-impl fmt::Debug for FuncInstance {
-	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-		match self {
-			&FuncInstance::Internal {
-				ref func_type,
-				ref module,
-				..
-			} => write!(
-				f,
-				"Internal {{ type={:?}, module={:?} }}",
-				func_type,
-				module
-			),
-			&FuncInstance::Host { ref func_type, .. } => {
-				write!(f, "Host {{ type={:?} }}", func_type)
-			}
-		}
-	}
-}
-
-impl FuncInstance {
-	pub fn func_type(&self) -> Rc<FunctionType> {
-		match *self {
-			FuncInstance::Internal { ref func_type, .. } |
-			FuncInstance::Host { ref func_type, .. } => Rc::clone(func_type),
-		}
-	}
-
-	pub fn body(&self) -> Option<Rc<FuncBody>> {
-		match *self {
-			FuncInstance::Internal { ref body, .. } => Some(Rc::clone(body)),
-			FuncInstance::Host { .. } => None,
-		}
-	}
-}
-
-impl FuncInstance {
-	pub fn invoke<St: 'static>(
-		func: Rc<FuncInstance>,
-		args: Vec<RuntimeValue>,
-		state: &mut St,
-	) -> Result<Option<RuntimeValue>, Error> {
-		enum InvokeKind {
-			Internal(FunctionContext),
-			Host(Rc<AnyFunc>, Vec<RuntimeValue>),
-		}
-
-		let result = match *func {
-			FuncInstance::Internal { ref func_type, .. } => {
-				let mut args = StackWithLimit::with_data(args, DEFAULT_VALUE_STACK_LIMIT);
-				let args = prepare_function_args(func_type, &mut args)?;
-				let context = FunctionContext::new(
-					Rc::clone(&func),
-					DEFAULT_VALUE_STACK_LIMIT,
-					DEFAULT_FRAME_STACK_LIMIT,
-					func_type,
-					args,
-				);
-				InvokeKind::Internal(context)
-			}
-			FuncInstance::Host { ref host_func, .. } => {
-				InvokeKind::Host(Rc::clone(host_func), args)
-			}
-		};
-
-		match result {
-			InvokeKind::Internal(ctx) => {
-				let mut interpreter = Interpreter::new(state);
-				interpreter.run_function(ctx)
-			}
-			InvokeKind::Host(host_func, args) => host_func.call_as_any(state as &mut Any, &args),
-		}
-	}
-}
-
-#[derive(Clone, Debug)]
-pub struct FuncBody {
-	pub locals: Vec<Local>,
-	pub opcodes: Opcodes,
-	pub labels: HashMap<usize, usize>,
-}
-
 #[derive(Default, Debug)]
 pub struct ModuleInstance {
 	types: RefCell<Vec<Rc<FunctionType>>>,
diff --git a/src/interpreter/table.rs b/src/interpreter/table.rs
index 03b3609..2ac3180 100644
--- a/src/interpreter/table.rs
+++ b/src/interpreter/table.rs
@@ -5,7 +5,7 @@ use parking_lot::RwLock;
 use elements::{TableType, ResizableLimits};
 use interpreter::Error;
 use interpreter::module::check_limits;
-use interpreter::store::FuncInstance;
+use interpreter::func::FuncInstance;
 
 /// Table instance.
 pub struct TableInstance {