diff --git a/compiler/compiler.go b/compiler/compiler.go
index a60341af..26f145b5 100644
--- a/compiler/compiler.go
+++ b/compiler/compiler.go
@@ -57,6 +57,7 @@ type Compiler struct {
 	targetData              llvm.TargetData
 	intType                 llvm.Type
 	i8ptrType               llvm.Type // for convenience
+	funcPtrAddrSpace        int
 	uintptrType             llvm.Type
 	initFuncs               []llvm.Value
 	interfaceInvokeWrappers []interfaceInvokeWrapper
@@ -125,6 +126,11 @@ func NewCompiler(pkgName string, config Config) (*Compiler, error) {
 	}
 	c.i8ptrType = llvm.PointerType(c.ctx.Int8Type(), 0)
 
+	dummyFuncType := llvm.FunctionType(c.ctx.VoidType(), nil, false)
+	dummyFunc := llvm.AddFunction(c.mod, "tinygo.dummy", dummyFuncType)
+	c.funcPtrAddrSpace = dummyFunc.Type().PointerAddressSpace()
+	dummyFunc.EraseFromParentAsFunction()
+
 	return c, nil
 }
 
@@ -462,7 +468,7 @@ func (c *Compiler) getLLVMType(goType types.Type) (llvm.Type, error) {
 		// {context, funcptr}
 		paramTypes = append(paramTypes, c.i8ptrType) // context
 		paramTypes = append(paramTypes, c.i8ptrType) // parent coroutine
-		ptr := llvm.PointerType(llvm.FunctionType(returnType, paramTypes, false), 0)
+		ptr := llvm.PointerType(llvm.FunctionType(returnType, paramTypes, false), c.funcPtrAddrSpace)
 		ptr = c.ctx.StructType([]llvm.Type{c.i8ptrType, ptr}, false)
 		return ptr, nil
 	case *types.Slice:
diff --git a/compiler/interface-lowering.go b/compiler/interface-lowering.go
index 52093233..73623709 100644
--- a/compiler/interface-lowering.go
+++ b/compiler/interface-lowering.go
@@ -304,7 +304,7 @@ func (p *lowerInterfacesPass) run() {
 			// interface value should already have returned false.
 			// Replace the function pointer with undef (which will then be
 			// called), indicating to the optimizer this code is unreachable.
-			use.ReplaceAllUsesWith(llvm.Undef(p.i8ptrType))
+			use.ReplaceAllUsesWith(llvm.Undef(p.uintptrType))
 			use.EraseFromParentAsInstruction()
 		} else if len(itf.types) == 1 {
 			// There is only one implementation of the given type.
@@ -314,12 +314,12 @@ func (p *lowerInterfacesPass) run() {
 			// There are multiple types implementing this interface, thus there
 			// are multiple possible functions to call. Delegate calling the
 			// right function to a special wrapper function.
-			bitcasts := getUses(use)
-			if len(bitcasts) != 1 || bitcasts[0].IsABitCastInst().IsNil() {
-				panic("expected exactly one bitcast use of runtime.interfaceMethod")
+			inttoptrs := getUses(use)
+			if len(inttoptrs) != 1 || inttoptrs[0].IsAIntToPtrInst().IsNil() {
+				panic("expected exactly one inttoptr use of runtime.interfaceMethod")
 			}
-			bitcast := bitcasts[0]
-			calls := getUses(bitcast)
+			inttoptr := inttoptrs[0]
+			calls := getUses(inttoptr)
 			if len(calls) != 1 || calls[0].IsACallInst().IsNil() {
 				panic("expected exactly one call use of runtime.interfaceMethod")
 			}
@@ -340,14 +340,14 @@ func (p *lowerInterfacesPass) run() {
 			// call, after selecting the right concrete type.
 			redirector := p.getInterfaceMethodFunc(itf, signature, call.Type(), paramTypes)
 
-			// Replace the old lookup/bitcast/call with the new call.
+			// Replace the old lookup/inttoptr/call with the new call.
 			p.builder.SetInsertPointBefore(call)
 			retval := p.builder.CreateCall(redirector, params, "")
 			if retval.Type().TypeKind() != llvm.VoidTypeKind {
 				call.ReplaceAllUsesWith(retval)
 			}
 			call.EraseFromParentAsInstruction()
-			bitcast.EraseFromParentAsInstruction()
+			inttoptr.EraseFromParentAsInstruction()
 			use.EraseFromParentAsInstruction()
 		}
 	}
@@ -542,22 +542,22 @@ func (p *lowerInterfacesPass) getSignature(name string) *signatureInfo {
 	return p.signatures[name]
 }
 
-// replaceInvokeWithCall replaces a runtime.interfaceMethod + bitcast with a
+// replaceInvokeWithCall replaces a runtime.interfaceMethod + inttoptr with a
 // concrete method. This can be done when only one type implements the
 // interface.
 func (p *lowerInterfacesPass) replaceInvokeWithCall(use llvm.Value, typ *typeInfo, signature *signatureInfo) {
-	bitcasts := getUses(use)
-	if len(bitcasts) != 1 || bitcasts[0].IsABitCastInst().IsNil() {
-		panic("expected exactly one bitcast use of runtime.interfaceMethod")
+	inttoptrs := getUses(use)
+	if len(inttoptrs) != 1 || inttoptrs[0].IsAIntToPtrInst().IsNil() {
+		panic("expected exactly one inttoptr use of runtime.interfaceMethod")
 	}
-	bitcast := bitcasts[0]
+	inttoptr := inttoptrs[0]
 	function := typ.getMethod(signature).function
-	if bitcast.Type() != function.Type() {
+	if inttoptr.Type() != function.Type() {
 		p.builder.SetInsertPointBefore(use)
-		function = p.builder.CreateBitCast(function, bitcast.Type(), "")
+		function = p.builder.CreateBitCast(function, inttoptr.Type(), "")
 	}
-	bitcast.ReplaceAllUsesWith(function)
-	bitcast.EraseFromParentAsInstruction()
+	inttoptr.ReplaceAllUsesWith(function)
+	inttoptr.EraseFromParentAsInstruction()
 	use.EraseFromParentAsInstruction()
 }
 
diff --git a/compiler/interface.go b/compiler/interface.go
index 3a2f64bf..f39bc105 100644
--- a/compiler/interface.go
+++ b/compiler/interface.go
@@ -203,7 +203,7 @@ func (c *Compiler) getTypeMethodSet(typ types.Type) (llvm.Value, error) {
 		}
 		methodInfo := llvm.ConstNamedStruct(interfaceMethodInfoType, []llvm.Value{
 			signatureGlobal,
-			llvm.ConstBitCast(fn, c.i8ptrType),
+			llvm.ConstPtrToInt(fn, c.uintptrType),
 		})
 		methods[i] = methodInfo
 	}
@@ -400,7 +400,7 @@ func (c *Compiler) getInvokeCall(frame *Frame, instr *ssa.CallCommon) (llvm.Valu
 		c.getMethodSignature(instr.Method),
 	}
 	fn := c.createRuntimeCall("interfaceMethod", values, "invoke.func")
-	fnCast := c.builder.CreateBitCast(fn, llvmFnType, "invoke.func.cast")
+	fnCast := c.builder.CreateIntToPtr(fn, llvmFnType, "invoke.func.cast")
 	receiverValue := c.builder.CreateExtractValue(itf, 1, "invoke.func.receiver")
 
 	args := []llvm.Value{receiverValue}
diff --git a/src/runtime/interface.go b/src/runtime/interface.go
index 3daf56d2..61d3114d 100644
--- a/src/runtime/interface.go
+++ b/src/runtime/interface.go
@@ -39,8 +39,8 @@ func interfaceTypeAssert(ok bool) {
 // See compiler/interface-lowering.go for details.
 
 type interfaceMethodInfo struct {
-	signature *uint8 // external *i8 with a name identifying the Go function signature
-	funcptr   *uint8 // bitcast from the actual function pointer
+	signature *uint8  // external *i8 with a name identifying the Go function signature
+	funcptr   uintptr // bitcast from the actual function pointer
 }
 
 // Pseudo function call used while putting a concrete value in an interface,
@@ -59,4 +59,4 @@ func interfaceImplements(typecode uintptr, interfaceMethodSet **uint8) bool
 
 // Pseudo function that returns a function pointer to the method to call.
 // See the interface lowering pass for how this is lowered to a real call.
-func interfaceMethod(typecode uintptr, interfaceMethodSet **uint8, signature *uint8) *uint8
+func interfaceMethod(typecode uintptr, interfaceMethodSet **uint8, signature *uint8) uintptr