diff --git a/src/kits/support/String.cpp b/src/kits/support/String.cpp
index ffa7e58190..e17c17cc34 100644
--- a/src/kits/support/String.cpp
+++ b/src/kits/support/String.cpp
@@ -14,14 +14,14 @@
 
 /*! String class supporting common string operations. */
 
+#include <String.h>
+
 #include <ctype.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <wctype.h>
 
 #include <Debug.h>
-#include <String.h>
 
 #include <utf8_functions.h>
 
@@ -1970,22 +1970,20 @@ BString::Trim()
 	const char* string = String();
 
 	// string is \0 terminated thus we don't need to check if we reached the end
-	uint32 startCount = 0;
-	while (iswspace(string[startCount]))
+	int32 startCount = 0;
+	while (isspace(string[startCount]))
 		startCount++;
 
-	uint32 endCount = 0;
-	while (endCount < originalLength - startCount
-		&& iswspace(string[originalLength - endCount - 1])) {
-		endCount++;
-	}
+	int32 endIndex = Length() - 1;
+	while (endIndex >= startCount && isspace(string[endIndex]))
+		endIndex--;
 
-	if (startCount == 0 && endCount == 0)
+	if (startCount == 0 && endIndex == Length() - 1)
 		return *this;
 
 	// We actually need to trim
 
-	ssize_t length = originalLength - startCount - endCount;
+	ssize_t length = endIndex + 1 - startCount;
 	ASSERT(length >= 0);	
 	if (startCount == 0 || length == 0) {
 		_MakeWritable(length, true);