diff --git a/src/comp/lib/llvm.rs b/src/comp/lib/llvm.rs
index 68ba8624268c..7010bc82f010 100644
--- a/src/comp/lib/llvm.rs
+++ b/src/comp/lib/llvm.rs
@@ -865,7 +865,7 @@ native mod llvm {
     fn LLVMRustParseBitcode(MemBuf: MemoryBufferRef) -> ModuleRef;
 
     /** FiXME: Hacky adaptor for lack of ULongLong in FFI: */
-    fn LLVMRustConstSmallInt(IntTy: TypeRef, N: uint, SignExtend: Bool) ->
+    fn LLVMRustConstInt(IntTy: TypeRef, N_hi: uint, N_lo: uint, SignExtend: Bool) ->
        ValueRef;
 
     fn LLVMRustAddPrintModulePass(PM: PassManagerRef, M: ModuleRef,
diff --git a/src/comp/middle/trans_common.rs b/src/comp/middle/trans_common.rs
index 276a7460f8cf..4b2791f66c81 100644
--- a/src/comp/middle/trans_common.rs
+++ b/src/comp/middle/trans_common.rs
@@ -725,7 +725,9 @@ fn T_opaque_chan_ptr() -> TypeRef { ret T_ptr(T_i8()); }
 fn C_null(t: TypeRef) -> ValueRef { ret llvm::LLVMConstNull(t); }
 
 fn C_integral(t: TypeRef, u: u64, sign_extend: Bool) -> ValueRef {
-    ret llvm::LLVMConstInt(t, u, sign_extend);
+    let u_hi = (u >> 32u64) as uint;
+    let u_lo = u as uint;
+    ret llvm::LLVMRustConstInt(t, u_hi, u_lo, sign_extend);
 }
 
 fn C_float(cx: @crate_ctxt, s: str) -> ValueRef {
diff --git a/src/rustllvm/RustWrapper.cpp b/src/rustllvm/RustWrapper.cpp
index c0553b3c1d9f..635030fd0adb 100644
--- a/src/rustllvm/RustWrapper.cpp
+++ b/src/rustllvm/RustWrapper.cpp
@@ -126,6 +126,16 @@ extern "C" LLVMValueRef LLVMRustConstSmallInt(LLVMTypeRef IntTy, unsigned N,
   return LLVMConstInt(IntTy, (unsigned long long)N, SignExtend);
 }
 
+extern "C" LLVMValueRef LLVMRustConstInt(LLVMTypeRef IntTy, 
+					 unsigned N_hi,
+					 unsigned N_lo,
+					 LLVMBool SignExtend) {
+  unsigned long long N = N_hi;
+  N <<= 32;
+  N |= N_lo;
+  return LLVMConstInt(IntTy, N, SignExtend);
+}
+
 extern bool llvm::TimePassesIsEnabled;
 extern "C" void LLVMRustEnableTimePasses() {
   TimePassesIsEnabled = true;
diff --git a/src/rustllvm/rustllvm.def.in b/src/rustllvm/rustllvm.def.in
index 9712ea603712..75d8dc8229e2 100644
--- a/src/rustllvm/rustllvm.def.in
+++ b/src/rustllvm/rustllvm.def.in
@@ -4,6 +4,7 @@ LLVMRustWriteOutputFile
 LLVMRustGetLastError
 LLVMRustGetHostTriple
 LLVMRustConstSmallInt
+LLVMRustConstInt
 LLVMRustParseBitcode
 LLVMRustPrintPassTimings
 LLVMRustEnableSegmentedStacks