diff --git a/llvm/extra.cpp b/llvm/extra.cpp
index aa98a17..9925028 100644
--- a/llvm/extra.cpp
+++ b/llvm/extra.cpp
@@ -254,7 +254,7 @@ void LLVMDisposeTargetMachine(LLVMTargetMachineRef tm){
 
 unsigned char* LLVMTargetMachineEmitFile(LLVMTargetMachineRef tmref,
                                          LLVMModuleRef modref,
-                                         int assembly, unsigned * lenp,
+                                         int assembly, size_t * lenp,
                                          std::string &error)
 {
     using namespace llvm;
@@ -352,7 +352,7 @@ LLVMTargetDataRef LLVMTargetMachineGetTargetData(LLVMTargetMachineRef tm)
 }
 
 unsigned char* LLVMGetNativeCodeFromModule(LLVMModuleRef module, int assembly,
-                                           unsigned * lenp, std::string &error)
+                                           size_t * lenp, std::string &error)
 {
     using namespace llvm;
     assert(lenp);
@@ -988,7 +988,7 @@ unsigned LLVMLinkModules(LLVMModuleRef dest, LLVMModuleRef src, unsigned int mod
 }
 #endif
 
-unsigned char *LLVMGetBitcodeFromModule(LLVMModuleRef module, unsigned *lenp)
+unsigned char *LLVMGetBitcodeFromModule(LLVMModuleRef module, size_t *lenp)
 {
     assert(lenp);
 
diff --git a/llvm/extra.h b/llvm/extra.h
index 87e0759..dc0a029 100644
--- a/llvm/extra.h
+++ b/llvm/extra.h
@@ -109,7 +109,7 @@ void LLVMDisposeTargetMachine(LLVMTargetMachineRef tm);
  */
 unsigned char* LLVMTargetMachineEmitFile(LLVMTargetMachineRef tmref,
                                          LLVMModuleRef modref,
-                                         int assembly, unsigned * lenp,
+                                         int assembly, size_t * lenp,
                                          std::string &error);
 
 /*
@@ -151,7 +151,7 @@ void LLVMPrintRegisteredTargetsForVersion();
  * Wraps TargetMachine::addPassesToEmitFile
  */
 unsigned char* LLVMGetNativeCodeFromModule(LLVMModuleRef module, int assembly,
-                                           unsigned * lenp, std::string &error);
+                                           size_t * lenp, std::string &error);
 
 /*
  * Wraps IRBuilder::CreateFence
@@ -446,7 +446,7 @@ unsigned LLVMLinkModules(LLVMModuleRef dest, LLVMModuleRef src,
 #endif
 /* Returns pointer to a heap-allocated block of `*len' bytes containing bit code
  * for the given module. NULL on error. */
-unsigned char *LLVMGetBitcodeFromModule(LLVMModuleRef module, unsigned *len);
+unsigned char *LLVMGetBitcodeFromModule(LLVMModuleRef module, size_t *len);
 
 /* Wraps llvm::sys::DynamicLibrary::LoadLibraryPermanently(). Returns 0 on
  * failure (with errmsg filled in) and 1 on success. Dispose error message after
diff --git a/llvm/wrap.cpp b/llvm/wrap.cpp
index 6e2024e..205acc9 100644
--- a/llvm/wrap.cpp
+++ b/llvm/wrap.cpp
@@ -108,7 +108,7 @@ void **make_array_from_list(PyObject *list, int n)
 }
 
 #define LIST_FROM_ARRAY_IMPL(TYPE)                                  \
-PyObject *make_list_from_ ## TYPE ## _array( TYPE *p, unsigned n)   \
+PyObject *make_list_from_ ## TYPE ## _array( TYPE *p, size_t n)   \
 {                                                                   \
     size_t i;                                                       \
     PyObject *list = PyList_New(n);                                 \