diff --git a/src/libCom/misc/epicsString.c b/src/libCom/misc/epicsString.c
index 28b3f3488..f5c61944d 100644
--- a/src/libCom/misc/epicsString.c
+++ b/src/libCom/misc/epicsString.c
@@ -171,11 +171,11 @@ size_t epicsStrnEscapedFromRawSize(const char *inbuf, size_t inlen)
 int epicsStrCaseCmp(const char *s1, const char *s2)
 {
     while (1) {
-        int ch1 = toupper(*s1);
-        int ch2 = toupper(*s2);
+        int ch1 = toupper((int) *s1);
+        int ch2 = toupper((int) *s2);
 
-        if (ch1 == 0) return (ch2 != 0);
-        if (ch2 == 0) return -1;
+        if (ch2 == 0) return (ch1 != 0);
+        if (ch1 == 0) return -1;
         if (ch1 < ch2) return -1;
         if (ch1 > ch2) return 1;
         s1++;
@@ -188,11 +188,11 @@ int epicsStrnCaseCmp(const char *s1, const char *s2, size_t len)
     size_t i = 0;
 
     while (i++ < len) {
-        int ch1 = toupper(*s1);
-        int ch2 = toupper(*s2);
+        int ch1 = toupper((int) *s1);
+        int ch2 = toupper((int) *s2);
 
-        if (ch1 == 0) return (ch2 != 0);
-        if (ch2 == 0) return -1;
+        if (ch2 == 0) return (ch1 != 0);
+        if (ch1 == 0) return -1;
         if (ch1 < ch2) return -1;
         if (ch1 > ch2) return 1;
         s1++;
diff --git a/src/libCom/test/epicsStringTest.c b/src/libCom/test/epicsStringTest.c
index e9dea2fb2..72944f7c6 100644
--- a/src/libCom/test/epicsStringTest.c
+++ b/src/libCom/test/epicsStringTest.c
@@ -56,8 +56,8 @@ MAIN(epicsStringTest)
 
     testOk1(epicsStrnCaseCmp(empty, "", 0) == 0);
     testOk1(epicsStrnCaseCmp(empty, "", 1) == 0);
-    testOk1(epicsStrnCaseCmp(space, empty, 1) < 0);
-    testOk1(epicsStrnCaseCmp(empty, space, 1) > 0);
+    testOk1(epicsStrnCaseCmp(space, empty, 1) > 0);
+    testOk1(epicsStrnCaseCmp(empty, space, 1) < 0);
     testOk1(epicsStrnCaseCmp(a, A, 1) == 0);
     testOk1(epicsStrnCaseCmp(a, A, 2) == 0);
     testOk1(epicsStrnCaseCmp(abcd, ABCD, 2) == 0);
@@ -65,17 +65,17 @@ MAIN(epicsStringTest)
     testOk1(epicsStrnCaseCmp(abcd, ABCD, 1000) == 0);
     testOk1(epicsStrnCaseCmp(abcd, ABCDE, 2) == 0);
     testOk1(epicsStrnCaseCmp(abcd, ABCDE, 4) == 0);
-    testOk1(epicsStrnCaseCmp(abcd, ABCDE, 1000)> 0);
+    testOk1(epicsStrnCaseCmp(abcd, ABCDE, 1000) < 0);
     testOk1(epicsStrnCaseCmp(abcde, ABCD, 2) == 0);
     testOk1(epicsStrnCaseCmp(abcde, ABCD, 4) == 0);
-    testOk1(epicsStrnCaseCmp(abcde, ABCD, 1000) < 0);
+    testOk1(epicsStrnCaseCmp(abcde, ABCD, 1000) > 0);
 
     testOk1(epicsStrCaseCmp(empty, "") == 0);
     testOk1(epicsStrCaseCmp(a, A) == 0);
     testOk1(epicsStrCaseCmp(abcd, ABCD) == 0);
-    testOk1(epicsStrCaseCmp(abcd, ABCDE) != 0);
-    testOk1(epicsStrCaseCmp(abcde, ABCD) != 0);
-    testOk1(epicsStrCaseCmp(abcde, "ABCDF") != 0);
+    testOk1(epicsStrCaseCmp(abcd, ABCDE) < 0);
+    testOk1(epicsStrCaseCmp(abcde, ABCD) > 0);
+    testOk1(epicsStrCaseCmp(abcde, "ABCDF") < 0);
 
     s = epicsStrDup(abcd);
     testOk(strcmp(s, abcd) == 0 && s != abcd, "epicsStrDup");