diff --git a/src/raw/windows.rs b/src/raw/windows.rs
index 6026588..b9f5b6a 100644
--- a/src/raw/windows.rs
+++ b/src/raw/windows.rs
@@ -34,6 +34,7 @@ lazy_static! {
     count: 0,
     previous: 0
     });
+	static ref OBTAINERS_COUNT : Mutex<usize> = Mutex::new(0);
 }
 
 
@@ -167,35 +168,45 @@ pub unsafe fn open_lib(name: &OsStr) -> Result<Handle, Error> {
 
 #[inline]
 pub unsafe fn addr_info_init(){
-	let process_handle = GetCurrentProcess();
-	let result = SymInitializeW(process_handle, null_mut(), TRUE);
-	assert_eq!(result, TRUE);
+	//calls to Sym* functions are not thread safe.
+	let mut lock = OBTAINERS_COUNT.lock().expect("Mutex got poisoned");
+	if *lock == 0 {
+		let process_handle = GetCurrentProcess();
+		let result = SymInitializeW(process_handle, null_mut(), TRUE);
+		assert_eq!(result, TRUE);
+	}
+	*lock += 1;
 }
 
 #[inline]
 pub unsafe fn addr_info_obtain(addr: * const ()) -> Result<AddressInfo, Error>{
     
 	let process_handle = GetCurrentProcess();
-    let module_base = SymGetModuleBase64(process_handle, addr as u64);
-	
-	if module_base == 0 {
-		return Err(Error::AddrNotMatchingDll(get_win_error()));
-	}
-    let mut buffer: [WCHAR; PATH_MAX as usize] = uninitialized();
-	
-    let path_len = GetModuleFileNameW(module_base as HMODULE, buffer.as_mut_ptr(), PATH_MAX);
-	
-    if path_len == 0 {
-        return Err(Error::AddrNotMatchingDll(get_win_error()));
-    }
 	
+	//calls to Sym* functions are not thread safe.
+	let mut buffer: [WCHAR; PATH_MAX as usize] = uninitialized();
 	let mut symbol_buffer: [u8; size_of::<SYMBOL_INFOW>() + MAX_SYMBOL_LEN * size_of::<WCHAR>()] = uninitialized();
-	let symbol_info: * mut SYMBOL_INFOW = symbol_buffer.as_mut_ptr() as  * mut SYMBOL_INFOW;
+	let (module_base, path_len, symbol_info, result) = {
+		let mut _lock = OBTAINERS_COUNT.lock().expect("Mutex got poisoned");
+		let module_base = SymGetModuleBase64(process_handle, addr as u64);
+	
+		if module_base == 0 {
+			return Err(Error::AddrNotMatchingDll(get_win_error()));
+		}
+		
 	
-	(*symbol_info).SizeOfStruct = size_of::<SYMBOL_INFOW>() as DWORD;
-	(*symbol_info).MaxNameLen = MAX_SYMBOL_LEN as DWORD;
-	let mut displacement:DWORD64 = 0;
-	let result = SymFromAddrW(process_handle, addr as DWORD64, &mut displacement, symbol_info);
+		let path_len = GetModuleFileNameW(module_base as HMODULE, buffer.as_mut_ptr(), PATH_MAX);		
+		if path_len == 0 {
+			return Err(Error::AddrNotMatchingDll(get_win_error()));
+		}
+		let symbol_info: * mut SYMBOL_INFOW = symbol_buffer.as_mut_ptr() as  * mut SYMBOL_INFOW;
+		
+		(*symbol_info).SizeOfStruct = size_of::<SYMBOL_INFOW>() as DWORD;
+		(*symbol_info).MaxNameLen = MAX_SYMBOL_LEN as DWORD;
+		let mut displacement:DWORD64 = 0;
+		let result = SymFromAddrW(process_handle, addr as DWORD64, &mut displacement, symbol_info);
+		(module_base, path_len, symbol_info, result)
+	};
 	
 	let os = if result == TRUE {
 		let name_len = (*symbol_info).NameLen as usize;
@@ -224,9 +235,13 @@ pub unsafe fn addr_info_obtain(addr: * const ()) -> Result<AddressInfo, Error>{
 
 #[inline]
 pub unsafe fn addr_info_cleanup(){
-	let process_handle = GetCurrentProcess();
-	let result = SymCleanup(process_handle);
-	assert_eq!(result, TRUE);
+	let mut lock = OBTAINERS_COUNT.lock().expect("Mutex got poisoned");
+	*lock -= 1;
+	if *lock == 0 {
+		let process_handle = GetCurrentProcess();
+		let result = SymCleanup(process_handle);
+		assert_eq!(result, TRUE);
+	}
 }
 
 #[inline]