diff --git a/gen/functions.cpp b/gen/functions.cpp
index 4a09ea3f..7896865e 100644
--- a/gen/functions.cpp
+++ b/gen/functions.cpp
@@ -528,7 +528,7 @@ void DtoDeclareFunction(FuncDeclaration* fdecl)
 
     // calling convention
     if (!vafunc && fdecl->llvmInternal != LLVMintrinsic)
-        func->setCallingConv(DtoCallingConv(f->linkage));
+        func->setCallingConv(DtoCallingConv(fdecl->loc, f->linkage));
     else // fall back to C, it should be the right thing to do
         func->setCallingConv(llvm::CallingConv::C);
 
diff --git a/gen/llvmhelpers.h b/gen/llvmhelpers.h
index 6764f7a9..cd959c6e 100644
--- a/gen/llvmhelpers.h
+++ b/gen/llvmhelpers.h
@@ -113,7 +113,7 @@ void DtoOverloadedIntrinsicName(TemplateInstance* ti, TemplateDeclaration* td, s
 ////////////////////////////////////////////
 
 /// convert DMD calling conv to LLVM
-unsigned DtoCallingConv(LINK l);
+unsigned DtoCallingConv(Loc loc, LINK l);
 
 ///
 TypeFunction* DtoTypeFunction(DValue* fnval);
diff --git a/gen/tocall.cpp b/gen/tocall.cpp
index a3af9fa3..faecfbe6 100644
--- a/gen/tocall.cpp
+++ b/gen/tocall.cpp
@@ -33,7 +33,7 @@ TypeFunction* DtoTypeFunction(DValue* fnval)
 
 //////////////////////////////////////////////////////////////////////////////////////////
 
-unsigned DtoCallingConv(LINK l)
+unsigned DtoCallingConv(Loc loc, LINK l)
 {
     if (l == LINKc || l == LINKcpp || l == LINKintrinsic)
         return llvm::CallingConv::C;
@@ -50,7 +50,10 @@ unsigned DtoCallingConv(LINK l)
     else if (l == LINKwindows)
         return llvm::CallingConv::X86_StdCall;
     else
-        assert(0 && "Unsupported calling convention");
+    {
+        error(loc, "unsupported calling convention");
+        fatal();
+    }
 }
 
 //////////////////////////////////////////////////////////////////////////////////////////
@@ -235,7 +238,7 @@ DValue* DtoCallFunction(Loc& loc, Type* resulttype, DValue* fnval, Expressions*
     bool nestedcall = tf->usesNest;
     bool dvarargs = (tf->linkage == LINKd && tf->varargs == 1);
 
-    unsigned callconv = DtoCallingConv(tf->linkage);
+    unsigned callconv = DtoCallingConv(loc, tf->linkage);
 
     // get callee llvm value
     LLValue* callable = DtoCallableValue(fnval);
diff --git a/gen/toobj.cpp b/gen/toobj.cpp
index 64472570..cf9c12f6 100644
--- a/gen/toobj.cpp
+++ b/gen/toobj.cpp
@@ -417,7 +417,7 @@ llvm::Function* build_module_ctor()
     const llvm::FunctionType* fnTy = llvm::FunctionType::get(LLType::VoidTy,argsTy,false);
     assert(gIR->module->getFunction(name) == NULL);
     llvm::Function* fn = llvm::Function::Create(fnTy, llvm::GlobalValue::InternalLinkage, name, gIR->module);
-    fn->setCallingConv(DtoCallingConv(LINKd));
+    fn->setCallingConv(DtoCallingConv(0, LINKd));
 
     llvm::BasicBlock* bb = llvm::BasicBlock::Create("entry", fn);
     IRBuilder<> builder(bb);
@@ -432,7 +432,7 @@ llvm::Function* build_module_ctor()
     for (size_t i=0; i<n; i++) {
         llvm::Function* f = gIR->ctors[i]->ir.irFunc->func;
         llvm::CallInst* call = builder.CreateCall(f,"");
-        call->setCallingConv(DtoCallingConv(LINKd));
+        call->setCallingConv(DtoCallingConv(0, LINKd));
     }
 
     // debug info end
@@ -462,7 +462,7 @@ static llvm::Function* build_module_dtor()
     const llvm::FunctionType* fnTy = llvm::FunctionType::get(LLType::VoidTy,argsTy,false);
     assert(gIR->module->getFunction(name) == NULL);
     llvm::Function* fn = llvm::Function::Create(fnTy, llvm::GlobalValue::InternalLinkage, name, gIR->module);
-    fn->setCallingConv(DtoCallingConv(LINKd));
+    fn->setCallingConv(DtoCallingConv(0, LINKd));
 
     llvm::BasicBlock* bb = llvm::BasicBlock::Create("entry", fn);
     IRBuilder<> builder(bb);
@@ -477,7 +477,7 @@ static llvm::Function* build_module_dtor()
     for (size_t i=0; i<n; i++) {
         llvm::Function* f = gIR->dtors[i]->ir.irFunc->func;
         llvm::CallInst* call = builder.CreateCall(f,"");
-        call->setCallingConv(DtoCallingConv(LINKd));
+        call->setCallingConv(DtoCallingConv(0, LINKd));
     }
 
     // debug info end
@@ -507,7 +507,7 @@ static llvm::Function* build_module_unittest()
     const llvm::FunctionType* fnTy = llvm::FunctionType::get(LLType::VoidTy,argsTy,false);
     assert(gIR->module->getFunction(name) == NULL);
     llvm::Function* fn = llvm::Function::Create(fnTy, llvm::GlobalValue::InternalLinkage, name, gIR->module);
-    fn->setCallingConv(DtoCallingConv(LINKd));
+    fn->setCallingConv(DtoCallingConv(0, LINKd));
 
     llvm::BasicBlock* bb = llvm::BasicBlock::Create("entry", fn);
     IRBuilder<> builder(bb);
@@ -522,7 +522,7 @@ static llvm::Function* build_module_unittest()
     for (size_t i=0; i<n; i++) {
         llvm::Function* f = gIR->unitTests[i]->ir.irFunc->func;
         llvm::CallInst* call = builder.CreateCall(f,"");
-        call->setCallingConv(DtoCallingConv(LINKd));
+        call->setCallingConv(DtoCallingConv(0, LINKd));
     }
 
     // debug info end