diff --git a/autoload.cpp b/autoload.cpp
index dd3dafbf3..e214acb0e 100644
--- a/autoload.cpp
+++ b/autoload.cpp
@@ -75,7 +75,7 @@ int autoload_t::load( const wcstring &cmd, bool reload )
     /* Do some work while locked, including determing the path variable */
     {
         scoped_lock locker(lock); 
-        path_var = env_get_string( env_var_name.c_str() );
+        path_var = env_get_string( env_var_name );
         
         /*
           Do we know where to look?
diff --git a/builtin_set.cpp b/builtin_set.cpp
index 1f64cb01e..c46be8b1a 100644
--- a/builtin_set.cpp
+++ b/builtin_set.cpp
@@ -316,7 +316,7 @@ static void print_variables(int include_values, int esc, int scope)
 		
 		if( include_values ) 
 		{
-			env_var_t value = env_get_string(key.c_str());
+			env_var_t value = env_get_string(key);
 			if( !value.missing() )
 			{
 				int shorten = 0;
diff --git a/complete.cpp b/complete.cpp
index ee348d07d..78282cc7a 100644
--- a/complete.cpp
+++ b/complete.cpp
@@ -1422,7 +1422,7 @@ static int complete_variable( const wchar_t *whole_var,
 
 		if( match || match_no_case )
 		{
-			const env_var_t value_unescaped = env_get_string( env_name.c_str() );
+			const env_var_t value_unescaped = env_get_string( env_name );
 			if( !value_unescaped.missing() )
 			{
 				wcstring comp;
diff --git a/env.cpp b/env.cpp
index e2e380a88..82547116d 100644
--- a/env.cpp
+++ b/env.cpp
@@ -1076,12 +1076,11 @@ const wchar_t *env_var_t::c_str(void) const {
     return wcstring::c_str();
 }
 
-env_var_t env_get_string( const wchar_t *key )
+env_var_t env_get_string( const wcstring &key )
 {
     scoped_lock lock(env_lock);
     
-	CHECK( key, 0 );    
-	if( wcscmp( key, L"history" ) == 0 )
+	if( key == L"history" )
 	{
         wcstring result;
 		const wchar_t *current;
@@ -1113,19 +1112,19 @@ env_var_t env_get_string( const wchar_t *key )
         
 		return result;
 	}
-	else if( wcscmp( key, L"COLUMNS" )==0 )
+	else if( key == L"COLUMNS" )
 	{
         return format_val((long)common_get_width());
 	}	
-	else if( wcscmp( key, L"LINES" )==0 )
+	else if( key == L"LINES" )
 	{
         return format_val((long)common_get_width());
 	}
-	else if( wcscmp( key, L"status" )==0 )
+	else if( key == L"status" )
 	{
         return format_val((long)proc_get_last_status());
 	}
-	else if( wcscmp( key, L"umask" )==0 )
+	else if( key == L"umask" )
 	{
         return format_string(L"0%0.3o", get_umask() );
 	}
diff --git a/env.h b/env.h
index a5ac97b48..acef82a6d 100644
--- a/env.h
+++ b/env.h
@@ -116,7 +116,7 @@ public:
 /**
  Gets the variable with the specified name, or an empty string if it does not exist.
  */
-env_var_t env_get_string( const wchar_t *key );
+env_var_t env_get_string( const wcstring &key );
 
 /**
    Returns 1 if the specified key exists. This can't be reliably done
diff --git a/env_universal.cpp b/env_universal.cpp
index 94e592a19..fef32fe7d 100644
--- a/env_universal.cpp
+++ b/env_universal.cpp
@@ -318,13 +318,11 @@ int env_universal_read_all()
 	}		
 }
 
-wchar_t *env_universal_get( const wchar_t *name )
+wchar_t *env_universal_get( const wcstring &name )
 {
 	if( !init)
 		return 0;
 
-	CHECK( name, 0 );
-	
 	return env_universal_common_get( name );
 }
 
diff --git a/env_universal.h b/env_universal.h
index 435fc4b72..fc05741dd 100644
--- a/env_universal.h
+++ b/env_universal.h
@@ -29,7 +29,7 @@ void env_universal_destroy();
 /**
    Get the value of a universal variable
 */
-wchar_t *env_universal_get( const wchar_t *name );
+wchar_t *env_universal_get( const wcstring &name );
 
 /**
    Get the export flag of the variable with the specified
diff --git a/env_universal_common.cpp b/env_universal_common.cpp
index d7dea877b..9098121dd 100644
--- a/env_universal_common.cpp
+++ b/env_universal_common.cpp
@@ -896,7 +896,7 @@ void env_universal_common_get_names( wcstring_list_t &lst,
 }
 
 
-wchar_t *env_universal_common_get( const wchar_t *name )
+wchar_t *env_universal_common_get( const wcstring &name )
 {
 	std::map<wcstring, var_uni_entry_t*>::const_iterator result = env_universal_var.find(name);
 
diff --git a/env_universal_common.h b/env_universal_common.h
index 908c5bae1..c6c1d74ee 100644
--- a/env_universal_common.h
+++ b/env_universal_common.h
@@ -181,7 +181,7 @@ void env_universal_common_remove( const wcstring &key );
    This function operate agains the local copy of all universal
    variables, it does not communicate with any other process.
 */
-wchar_t *env_universal_common_get( const wchar_t *name );
+wchar_t *env_universal_common_get( const wcstring &name );
 
 /**
    Get the export flag of the variable with the specified