diff --git a/lib/Target/ARM/ARMFastISel.cpp b/lib/Target/ARM/ARMFastISel.cpp
index b545dbc..29fcd40 100644
--- a/lib/Target/ARM/ARMFastISel.cpp
+++ b/lib/Target/ARM/ARMFastISel.cpp
@@ -2922,6 +2922,7 @@
       return false;
 
     EVT ArgVT = TLI.getValueType(ArgTy);
+    if (!ArgVT.isSimple()) return false;
     switch (ArgVT.getSimpleVT().SimpleTy) {
     case MVT::i8:
     case MVT::i16:
diff --git a/lib/Target/X86/X86FastISel.cpp b/lib/Target/X86/X86FastISel.cpp
index ed17b11..b5c3270 100644
--- a/lib/Target/X86/X86FastISel.cpp
+++ b/lib/Target/X86/X86FastISel.cpp
@@ -1555,6 +1555,7 @@
       return false;
 
     EVT ArgVT = TLI.getValueType(ArgTy);
+    if (!ArgVT.isSimple()) return false;
     switch (ArgVT.getSimpleVT().SimpleTy) {
     case MVT::i32:
     case MVT::i64: