diff --git a/lib/Analysis/Lint.cpp b/lib/Analysis/Lint.cpp
index 83bdf52..6e765a7 100644
--- a/lib/Analysis/Lint.cpp
+++ b/lib/Analysis/Lint.cpp
@@ -412,14 +412,26 @@
   }
 
   if (TD) {
-    if (Align == 0 && Ty) Align = TD->getABITypeAlignment(Ty);
+    if (Align == 0 && Ty && Ty->isSized())
+      Align = TD->getABITypeAlignment(Ty);
 
     if (Align != 0) {
-      unsigned BitWidth = TD->getTypeSizeInBits(Ptr->getType());
-      APInt KnownZero(BitWidth, 0), KnownOne(BitWidth, 0);
-      ComputeMaskedBits(Ptr, KnownZero, KnownOne, TD);
-      Assert1(!(KnownOne & APInt::getLowBitsSet(BitWidth, Log2_32(Align))),
-              "Undefined behavior: Memory reference address is misaligned", &I);
+      int64_t Offset = 0;
+      if (Value *Base = GetPointerBaseWithConstantOffset(Ptr, Offset, *TD)) {
+        unsigned BaseAlign = 0;
+        if (AllocaInst *AI = dyn_cast<AllocaInst>(Base)) {
+          BaseAlign = AI->getAlignment();
+          if (BaseAlign == 0 && AI->getAllocatedType()->isSized())
+            BaseAlign = TD->getABITypeAlignment(AI->getAllocatedType());
+        } else if (GlobalValue *GV = dyn_cast<GlobalVariable>(Base)) {
+          BaseAlign = GV->getAlignment();
+          if (BaseAlign == 0 && GV->getType()->getElementType()->isSized())
+            BaseAlign = TD->getABITypeAlignment(GV->getType()->getElementType());
+        }
+        Assert1((!BaseAlign || Align <= MinAlign(BaseAlign, Offset)),
+                "Undefined behavior: Memory reference address is misaligned",
+                &I);
+      }
     }
   }
 }
diff --git a/test/Other/lint.ll b/test/Other/lint.ll
index c84f56f..f6787e9 100644
--- a/test/Other/lint.ll
+++ b/test/Other/lint.ll
@@ -11,6 +11,8 @@
 @CG = constant i32 7
 
 define i32 @foo() noreturn {
+  %buf = alloca i8
+  %buf2 = alloca {i8, i8}, align 2
 ; CHECK: Caller and callee calling convention differ
   call void @bar()
 ; CHECK: Null pointer dereference
@@ -26,8 +28,10 @@
 ; CHECK: Address one pointer dereference
   store i32 0, i32* inttoptr (i64 1 to i32*)
 ; CHECK: Memory reference address is misaligned
-  %x = inttoptr i32 1 to i32*
-  load i32* %x, align 4
+  store i8 0, i8* %buf, align 2
+; CHECK: Memory reference address is misaligned
+  %gep = getelementptr {i8, i8}* %buf2, i32 0, i32 1
+  store i8 0, i8* %gep, align 2
 ; CHECK: Division by zero
   %sd = sdiv i32 2, 0
 ; CHECK: Division by zero