diff --git a/src/tests/kits/support/bmemoryio/MallocWriteTest.cpp b/src/tests/kits/support/bmemoryio/MallocWriteTest.cpp
index d4182418f1..d84abc3100 100644
--- a/src/tests/kits/support/bmemoryio/MallocWriteTest.cpp
+++ b/src/tests/kits/support/bmemoryio/MallocWriteTest.cpp
@@ -23,7 +23,6 @@ MallocWriteTest::PerformTest(void)
 	
 	BMallocIO mem;	
 	ssize_t err;
-	off_t pos;
 	
 	NextSubTest();
 	err = mem.Write(writeBuf, 7);
diff --git a/src/tests/kits/support/bstring/StringAccessTest.cpp b/src/tests/kits/support/bstring/StringAccessTest.cpp
index 772e854b91..772e03dd06 100644
--- a/src/tests/kits/support/bstring/StringAccessTest.cpp
+++ b/src/tests/kits/support/bstring/StringAccessTest.cpp
@@ -23,12 +23,12 @@ StringAccessTest::PerformTest(void)
 	NextSubTest();
 	BString string("Something"B_UTF8_ELLIPSIS);
 	CPPUNIT_ASSERT(string.CountChars() == 10);
-	CPPUNIT_ASSERT(string.Length() == strlen(string.String()));
+	CPPUNIT_ASSERT((unsigned)string.Length() == strlen(string.String()));
 
 	NextSubTest();
 	BString string2("ABCD");
 	CPPUNIT_ASSERT(string2.CountChars() == 4);
-	CPPUNIT_ASSERT(string2.Length() == strlen(string2.String()));
+	CPPUNIT_ASSERT((unsigned)string2.Length() == strlen(string2.String()));
 
 	NextSubTest();
 	static char s[64];
@@ -36,7 +36,7 @@ StringAccessTest::PerformTest(void)
 	strcat(s, B_UTF8_SMILING_FACE);
 	BString string3(s);
 	CPPUNIT_ASSERT(string3.CountChars() == 2);	
-	CPPUNIT_ASSERT(string3.Length() == strlen(string3.String()));
+	CPPUNIT_ASSERT((unsigned)string3.Length() == strlen(string3.String()));
 	
 	//An empty string
 	NextSubTest();
diff --git a/src/tests/kits/support/bstring/StringAssignTest.cpp b/src/tests/kits/support/bstring/StringAssignTest.cpp
index 9fe5742d66..31f8be27cf 100644
--- a/src/tests/kits/support/bstring/StringAssignTest.cpp
+++ b/src/tests/kits/support/bstring/StringAssignTest.cpp
@@ -100,17 +100,15 @@ StringAssignTest::PerformTest(void)
 	CPPUNIT_ASSERT(strcmp(newstring.String(), "") == 0);
 	delete str;
 
-	const int32 OUT_OF_MEM_VAL = 2*1000*1000*1000;
 #ifndef TEST_R5
+	const int32 OUT_OF_MEM_VAL = 2*1000*1000*1000;
 	//SetTo(char, int32) with excessive length:
 	NextSubTest();
 	str = new BString("dummy");
 	str->SetTo('C', OUT_OF_MEM_VAL);
 	CPPUNIT_ASSERT(strcmp(str->String(), "dummy") == 0);
 	delete str;
-#endif
 
-#ifndef TEST_R5
 	//SetTo(char*, int32) with excessive length:
 	NextSubTest();
 	str = new BString("dummy");
diff --git a/src/tests/kits/support/bstring/StringConstructionTest.cpp b/src/tests/kits/support/bstring/StringConstructionTest.cpp
index 3412bd25fb..2443032464 100644
--- a/src/tests/kits/support/bstring/StringConstructionTest.cpp
+++ b/src/tests/kits/support/bstring/StringConstructionTest.cpp
@@ -32,7 +32,7 @@ StringConstructionTest::PerformTest(void)
 	NextSubTest();
 	string = new BString(str);
 	CPPUNIT_ASSERT(strcmp(string->String(), str) == 0);
-	CPPUNIT_ASSERT(string->Length() == strlen(str));
+	CPPUNIT_ASSERT((unsigned)string->Length() == strlen(str));
 	delete string;
 	
 	//BString(NULL)
@@ -61,7 +61,7 @@ StringConstructionTest::PerformTest(void)
 	NextSubTest();
 	string = new BString(str, 255);
 	CPPUNIT_ASSERT(strcmp(string->String(), str) == 0);
-	CPPUNIT_ASSERT(string->Length() == strlen(str));
+	CPPUNIT_ASSERT((unsigned)string->Length() == strlen(str));
 	delete string;	
 }